# Patent

## Title
Flux-cored wire for gas-shielded arc welding, method for welding steel for very low temperature use, and method for manufacturing weld joint

## Abstract

[Object] There is provided a flux-cored wire capable of obtaining a weld metal having excellent low temperature toughness and improving welding efficiency, in which preheating performed for preventing cold cracking can be omitted or simplified.
[Means for Solving Problems] The flux-cored wire includes one or more of CaF2, BaF2, SrF2, MgF2, and LiF and, when a total amount thereof is defined as α, the α is 2.0% to 7.0%, by mass %, with respect to a total mass of the flux-cored wire, one or more of a Ti oxide, a Si oxide, a Mg oxide, an Al oxide, a Zr oxide, and a Ca oxide are included in the flux-cored wire, and when a total amount thereof is defined as β, the β is 0.2% to 0.9%, by mass %, with respect to the total mass of the flux-cored wire, a ratio of an amount of the CaF2 with respect to the α is 0.90 or more, and a ratio of the α with respect to the β is 3.0 or more and 15.0 or less.

## Background
This application is a continuation-in-part application of International Patent Application No. PCT/JP2013/080284, filed Nov. 8, 2013, and claims priority to Japanese Patent Application No. 2014-220853, filed Oct. 29, 2014, each of which is incorporated by reference in its entirety.


TECHNICAL FIELD OF THE INVENTION
The present invention relates to a flux-cored wire used in gas-shielded arc welding of Ni steel for very low temperature use containing 5.5% to 9.5% of Ni, which is used for an LNG storage tank, a chemical plant, or the like, and particularly relates to a flux-cored wire for gas-shielded arc welding, capable of obtaining a weld metal having excellent low temperature toughness and improving welding efficiency, and having excellent cold cracking resistance, a method for welding steel for very low temperature use using the same, and a method for manufacturing a welded joint.
RELATED ART
In recent years, there has been an increasing demand for natural gas having less carbon dioxide emissions than that of oil, coal, or the like resulting from tightening of carbon dioxide emission regulations due to problems including global warming, and with the increasing demand for natural gas, demand for constructing an LNG storage tank has also been increasing worldwide. As steel used for an LNG storage tank, in order to meet demand for securing toughness at a very low temperature of −196° C., Ni-based steel for low temperature use including 5.5% to 9.5% of Ni is used.
In regard to welding for the Ni-based steel for low temperature use, because of the necessity of satisfying rigorous safety regulations, a Ni-based alloy welding material including 60% to 80% of Ni is used. However, since containing a large amount of Ni, the Ni-based alloy welding material is very expensive. Further, since the Ni-based alloy welding material has poor fluidity in a molten state, weld defects such as incomplete fusion is easily generated. In addition, since welding is performed with a low heat input to prevent weld defects, there is a problem in welding efficiency.
Further, in order to reduce welding material costs, when the amount of Ni is reduced to about 5.5% to 9.5%, which is the same level as Ni-based steel for low temperature use, the weld metal has a very hard martensite structure and a problem of cold cracking arises. The cold cracking does not occur in a Ni-based alloy welding material in which a structure of the weld metal is an austenite structure. The preheating performed for preventing cold cracking is a new problem in reduction of welding costs.
Under the circumstances, as a welding wire of steel for very low temperature use, for example, the following wires have been suggested.
In Patent Document 1, there is disclosed a flux-cored wire in which a Ni-based alloy material is used as an outer steel sheath. However, the amount of Ni is 60% to 70% and a welding material cost reduction has not been achieved.
In Patent Document 2, there is disclosed a welding material in which the amount of Ni is 7.5% to 12.0%. However, TIG welding which has low welding efficiency is employed as a welding method and thus welding efficiency has not been improved.
In Patent Document 3, there is disclosed a wire which is a welding material in which the amount of Ni is 8% to 13%, and has excellent welding efficiency by reducing welding material costs and applying submerged arc welding thereto. However, since submerged arc welding is employed as a welding method, an obtainable weld metal has 250 ppm of oxygen, which is a large amount, and accordingly, the absorbed energy at −196° C. is low. Thus, sufficient low temperature toughness cannot be secured. In addition, any examination of cold cracking as a problem caused in this amount of Ni has not been conducted.
In Non-Patent Document 1, a technology is disclosed which obtains a weld metal having a low oxygen content at the same level as in TIG welding, by performing MIG welding with a 100% Ar shielding gas using a solid wire of an iron alloy in which the amount of Ni is reduced to about 10%. In this technology, the amounts of P and S in the wire are significantly reduced, thus toughness can be secured. However, in the experiments conducted by the present inventors, there are defects such as a large amount of diffusible hydrogen being included in the weld metal obtained by the method in Non-Patent Document 1 and cold cracking resistance being deteriorated. In addition, since the wire described in the Non-Patent Document 1 is a solid wire in which Rem addition is required, there are other defects of spattering being violent and welding efficiency being deteriorated during welding.
Accordingly, as a welding wire of steel for very low temperature use, the development of a welding wire capable of reducing welding material costs and improving welding efficiency, and having excellent cold cracking resistance has been in strong demand.
PRIOR ART DOCUMENT
Patent Document


    [Patent Document 1] Japanese Unexamined Patent Application, First Publication No. 2008-246507
    [Patent Document 2] Japanese Unexamined Patent Application, First Publication No. H09-253860
    [Patent Document 3] Japanese Unexamined Patent Application, First Publication No. 2008-161932


Non-Patent Document


    [Non-Patent Document 1] Kazuo Agusa, Masaaki Kosho et al., “Matching Ferritic Filler MIG Welding of 9% Ni Steel”, Kawasaki Steel Giho, vol. 14, No. 3 (1982)


DISCLOSURE OF THE INVENTION
Problems to be Solved by the Invention
When there is an attempt to obtain a weld metal having excellent low temperature toughness even in a case in which the amount of Ni of a welding wire for consumable electrode type gas-shielded arc welding having excellent welding efficiency is reduced, oxygen penetrating into the weld metal from an active gas included in the shielding gas becomes a problem.
In gas-shielded arc welding, as a shielding gas, Ar-10% to 30% CO2 (that is, including 10% to 30% of CO2 by volume fraction, and a remainder including a mixed gas of Ar), 100% CO2, Ar-2% O2, or the like is generally used. 2% or more of CO2 or O2, which is an active gas, is included in the gas. This is because arcs are unstable and a sound weld metal without weld defects cannot be obtained by using only an inert gas.
On the other hand, these active gases are ionized by welding arcs and the ionized oxygen enter the weld metal, and thus, when the active gases are mixed, the amount of oxygen in the weld metal increases. When the amount of oxygen in the weld metal increases, the absorbed energy at a ductile fracture decreases.
As a welding material for steel for very low temperature use, when a welding material in which the amount of Ni is reduced to the same level as Ni steel containing 5.5% to 9.5% of Ni is used as a base metal, it is difficult to secure the absorbed energy at ductile fracture. Thus, a welding method capable of obtaining a weld metal having a small amount of oxygen is required. However, a welding wire capable of obtaining a sound weld metal by gas-shielded arc welding using a shielding gas in which the amount of an active mixed gas is reduced or using only an inert gas has not yet been realized.
In non-consumable electrode type TIG welding, a sound weld metal can be obtained and the amount of oxygen in the weld metal is reduced. However, there are problems in that the welding efficiency is very low compared to consumable electrode type gas-shielded arc welding and welding costs increase in the TIG welding.
Further, since the weld metal in which the amount of Ni is reduced to the same level as Ni steel containing 5.5% to 9.5% of Ni has a very hard martensite structure in the welding material, there is a problem of cold cracking.
In order to prevent cold cracking, preheating is required. The preheating is also a cause of deteriorating welding efficiency, but in the related art, any examination of cold cracking resistance has not been conducted.
The present invention has been made in consideration of the above-described problems in the related art and an object thereof is to provide a flux-cored wire for gas-shielded arc welding capable of significantly reducing welding material costs by reducing the amount of Ni to the same level as Ni steel containing 5.5% to 9.5% of Ni, and obtaining a weld metal having excellent low temperature toughness at −196° C. even when gas-shielded arc welding having excellent welding efficiency is applied. In addition, another object thereof is to provide a flux-cored wire for gas-shielded arc welding not requiring preheating for preventing cold cracking or capable of significantly reducing preheating, and a method for welding steel for very low temperature use using the same.
Means for Solving the Problem
As a result of intensive investigations to solve the above-described problems, the present inventors have found that when a flux-cored wire in which the amount of Ni is reduced to the same level as Ni steel containing 5.5% to 9.5% of Ni has a slag composition having fluoride as a main composition, it is possible to (i) obtain a sound weld metal in which arcs are stable and an amount of oxygen is small even with gas-shielded arc welding using a pure Ar gas or a mixed gas in which a ratio of oxygen is less than 2% in a pure Ar gas, as a shielding gas, and to (ii) obtain excellent Charpy absorbed energy at −196° C. by significantly reducing an alloy composition filled in a flux, using an outer steel sheath containing 6% to 16% of Ni, further reducing the amount of oxygen in a weld metal, and then, forming the most suitable composition for a weld metal obtained by this welding method with C, Si, Mn, and other alloying elements.
Further, it has been found that the amount of diffusible hydrogen in the weld metal can be significantly reduced by the use of the flux-cored wire according to the present invention.
Accordingly, the flux-cored wire, capable of obtaining a weld metal having excellent low temperature toughness, achieving high welding efficiency, and omitting or simplifying preheating performed for preventing cold cracking in welding of Ni steel containing 5.5% to 9.5% of Ni, has been found and further investigations have been conducted based on the findings. Therefore, the present invention has been accomplished.
(1) According to an aspect of the present invention, a flux-cored wire for gas-shielded arc welding is provided including an outer steel sheath; and a flux with which the outer steel sheath is filled, in which one or more of CaF2, BaF2, SrF2, MgF2, and LiF, which are metal fluorides, are included in the flux-cored wire and, when a total amount thereof is defined as α, the α is 2.0% to 7.0%, by mass %, with respect to a total mass of the flux-cored wire, one or more of a Ti oxide, a Si oxide, a Mg oxide, an Al oxide, a Zr oxide, and a Ca oxide, which are metal oxides, are included in the flux-cored wire and, when a total amount thereof is defined as β, the β is 0.2% to 0.9%, by mass %, with respect to the total mass of the flux-cored wire, one or more of CaCO3, BaCO3, SrCO3, MgCO3, and Li2CO3, which are metal carbonates, are included in the flux-cored wire and a total amount thereof is less than 0.6%, by mass %, with respect to the total mass of the flux-cored wire, a ratio of an amount of the CaF2 with respect to the α is 0.90 or more, a ratio of the α with respect to the β is 3.0 or more and 15.0 or less, an amount of the Ti oxide is 0% to 0.4%, by mass %, with respect to the total mass of the flux-cored wire, an amount of the Si oxide is 0.2% to 0.5%, by mass %, with respect to the total mass of the flux-cored wire, an amount of the Ca oxide is less than 0.20%, by mass %, with respect to the total mass of the flux-cored wire, an amount of an arc stabilizer in the flux is 0% to 0.50%, by mass %, with respect to the total mass of the flux-cored wire, an amount of an iron powder in the flux is less than 5%, by mass %, with respect to the total mass of the flux-cored wire, chemical compositions except the metal fluorides, the metal oxides, and the metal carbonates include, by mass %, with respect to the total mass of the flux-cored wire, C: 0.003% to 0.040%; Si: 0.05% to 0.40%; Mn: 0.2% to 0.8%; Al: 0.003% to 0.050%; Ni: 6.0% to 16.0%; P: 0.02% or less; S: 0.01% or less; Cu: 0% to 0.5%; Cr: 0% to 0.5%; Mo: 0% to 0.5%; V: 0% to 0.2%; Ti: 0% to 0.1%; Nb: 0% to 0.1%; B: 0% to 0.01%; Mg: 0% to 0.6%; REM: 0 to 0.0500%; and a remainder: Fe and an impurity, a SM defined by the below expression a is 0.3% to 1.0%, and Ceq defined by the below expression b is 0.250% to 0.525%,

SM=[Si]+[Mn]:  (Expression a),

Ceq=[C]+( 1/24)[Si]+(1⁄6)[Mn]+( 1/40)[Ni]+(1⁄5)[Cr]+(1⁄4)[Mo]+( 1/14)[V]:  (Expression b), and

in the expressions a and b, elements noted in brackets express amounts (mass %) of the elements, respectively.
(2) In the flux-cored wire for gas-shielded arc welding according to (1), the flux-cored wire may include the outer steel sheath including Ni and the flux filled therein, and an amount of Ni in the outer steel sheath may be 6% to 18%, by mass %, with respect to the total mass of the outer steel sheath.
(3) In the flux-cored wire for gas-shielded arc welding according to (1) or (2), an amount of REM in the flux-cored wire may be 0.0100% or less, by mass %, with respect to the total mass of the flux-cored wire.
(4) In the flux-cored wire for gas-shielded arc welding according to any one of (1) to (3), the amount of the Ca oxide in the flux-cored wire may be less than 0.10%, by mass %, with respect to the total mass of the flux-cored wire.
(5) In the flux-cored wire for gas-shielded arc welding according to any one of (1) to (4), a tensile strength of a weld metal may be 660 MPa to 900 MPa in a tensile test to the weld metal regulated in Japanese Industrial Standards JIS Z 3111-2005 in the gas-shielded arc welding using the flux-cored wire.
(6) In the flux-cored wire for gas-shielded arc welding according to any one of (1) to (5), a slit-shaped gap may exist in the outer steel sheath of the flux-cored wire.
(7) In the flux-cored wire for gas-shielded arc welding according to any one of (1) to (5), a slit-shaped gap may not exist in the outer steel sheath of the flux-cored wire.
(8) In the flux-cored wire for gas-shielded arc welding according to any one of (1) to (7), a perfluoropolyether oil may be applied on a surface of the outer steel sheath of the flux-cored wire.
(9) According to a second aspect of the present invention, a method for welding steel for very low temperature use is provided, in which welding is performed with the flux-cored wire for gas-shielded arc welding according to any one of (1) to (8), and with any one of a pure Ar gas, a mixed gas of Ar and 1.5 volume % or less of O2 or CO2, a pure He gas, and a mixed gas of He and 1.5 volume % or less of O2 or CO2 as a shielding gas.
(10) According to a third aspect of the present invention, a method for manufacturing a weld joint is provided, in which a steel plate in which a thickness is 6 mm to 100 mm, an amount of Ni is 5.5 mass % to 9.5 mass %, and a tensile strength is 660 MPa to 900 MPa is welded with the flux-cored wire for gas-shielded arc welding according to any one of (1) to (8), and with any one of a pure Ar gas, a mixed gas of Ar and 1.5 volume % or less of O2 or CO2, a pure He gas, and a mixed gas of He and 1.5 volume % or less of O2 or CO2 as a shielding gas.
Effects of the Invention
According to each of the aspects of the present invention, gas-shielded arc welding capable of significantly reducing welding material costs by reducing the amount of Ni to the flux-cored wire used for welding Ni-based steel for low temperature use containing about 5.5% to 9.5% of Ni to the same level as Ni-based steel for low temperature use and achieving excellent welding efficiency can be applied, and further, a weld metal having excellent low temperature toughness at −196° C. can be obtained by reducing the alloy composition of the flux to fill the inside of the wire and the amount of oxygen in the weld metal. Further, it is possible to provide a flux-cored wire in which preheating for preventing cold cracking is not required or preheating can be significantly reduced, a method for welding steel for very low temperature use using the same, and a method for manufacturing a welding joint.



BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a view showing a relationship between SM and Charpy absorbed energy at −196° C. (when the entire outer steel sheath is made of mild steel).
FIG. 2 is a view showing a relationship between SM and Charpy absorbed energy at −196° C. (when the entire outer steel sheath is made of Ni-containing steel).
FIG. 3 is a view showing a relationship between an amount of CaO and an amount of diffusible hydrogen (when the entire outer steel sheath is made of mild steel).
FIG. 4 is a view showing a relationship between an amount of CaO and an amount of diffusible hydrogen (when the entire outer steel sheath is made of Ni-containing steel).
FIG. 5 is a cross-sectional view of a cut wire.
FIG. 6 is a view showing a relationship between an amount of oxygen in a weld metal and Charpy absorbed energy at −196° C. (when the entire outer steel sheath is made of mild steel).
FIG. 7 is a view showing a relationship between an amount of oxygen in a weld metal and Charpy absorbed energy at −196° C. (when the entire outer steel sheath is made of Ni-containing steel).
FIG. 8 is a view showing a position where a test piece is collected in an example (JIS Z 3111-2005).



EMBODIMENTS OF THE INVENTION
A weld metal of Ni-based steel for low temperature use requires low temperature toughness at −196° C. and an amount of oxygen in the weld metal needs to be reduced to secure absorbed energy at −196° C.
As a method for reducing the amount of oxygen in the weld metal, the use of gas-shielded arc welding using an inert gas may be considered. However, since arcs are unstable and a sound weld metal without weld defects is hardly obtained, the gas-shielded arc welding has not been used.
Thus, only a Ni-based alloy welding material or means for using a method in which welding efficiency is very low such as TIG welding has been used. The former has a problem of very high welding material costs, and the latter has a problem of a very low welding efficiency. Thus, a welding material in which welding material costs are low and welding efficiency is high has not been realized.
The present inventors have performed welding of Ni-based steel for low temperature use using wires, which are a flux-cored wire in which the amount of Ni is reduced at the same level as Ni-based steel for low temperature use and which are prepared with different amounts of CaF2 and a metal oxide at various ratios and further with different amounts of C, Si, Mn, and other alloy elements at various ratios, by gas-shielded arc welding using an inert gas.
As a result, (i) in a specific range of the amounts of CaF2 and the metal oxide, arcs are stable even in the gas-shielded arc welding using an inert gas and a sound weld metal can be obtained. (ii) Not only can an inert gas be used but also the use of an outer steel sheath including Ni enables significant reduction in the amount of oxygen in the weld metal. (iii) In a specific range of the amounts of C, Si, Mn, and other alloy elements, excellent low temperature toughness at −196° C. can be obtained. (iv) In a specific range of the amount of CaF2, the amount of diffusible hydrogen in the weld metal can be significantly reduced. (v) Preheating required for preventing cold cracking which is a problem arising when the amount of Ni is reduced to the same level as Ni-based steel for low temperature use is not required or the preheating can be significantly reduced. The above-described points (i) to (v) have been found.
The present invention has been made based on the results of the above investigations and reasons for limiting characterized technical requirements and preferable embodiments with respect to a flux-cored wire according to an embodiment will be sequentially described below.
First, the reasons why the amounts of an alloy composition, a metal deoxidizing composition, and each composition contained in an outer steel sheath constituting the flux-cored wire of the embodiment and a flux are limited will be described.
In the following description, unless otherwise specified, “%” means “mass % and an amount of each composition means a composition amount which is total mass % of each composition in the outer steel sheath and the flux with respect to a total mass of the wire.
(C: 0.003% to 0.040%)
C is an element for increasing strength and 0.003% or more of C needs to be contained to secure the strength. In order to increase the strength, the lower limit of the amount of C may be 0.005%, 0.008%, 0.010%, or 0.013%. On the other hand, a weld metal containing 6% to 16% of Ni has a hard martensite structure. An influence of C affecting the hardness of martensite is very significant and when the amount of C is more than 0.040%, the weld metal becomes very hard and the toughness significantly decreases. Thus, the upper limit of the amount of C is 0.040%. In order to stably secure the toughness, the upper limit of the amount of C may be 0.035% or 0.030%.
(Si: 0.05% to 0.40%)
Si is an element required for increasing the cleanliness of the weld metal and preventing the generation of weld defects such as a blowhole. In order to obtain these effects, 0.05% or more of Si needs to be contained. In order to prevent the generation of the weld defects, the lower limit of the amount of Si may be 0.09% or 0.14%. On the other hand, Si is easily micro-segregated in the weld metal containing 6% to 16% of Ni. When the amount of Si is more than 0.40%, remarkable embrittlement is caused in the segregated portion, and thus, 0.40% is the upper limit. In addition, the upper limit of the amount of Si may be 0.35% or 0.30% to stably secure the toughness of the weld metal.
(Mn: 0.2% to 0.8%)
Mn is an element required for increasing the cleanliness of the weld metal and detoxifying S by forming MnS to improve toughness. In order to obtain these effects, 0.2% or more of Mn needs to be contained. In order to further improve the toughness, the lower limit of the amount of Mn may be 0.3%, 0.35%, or 0.4%. On the other hand, Mn is easily micro-segregated in the weld metal containing 6% to 16% of Ni. When the amount of Mn is more than 0.8%, remarkable embrittlement is caused in the segregated portion, and thus, 0.8%, is set as an upper limit. In addition, the upper limit of the amount of Mn may be 0.7%, 0.6%, or 0.5% to stably secure the toughness of the weld metal.
(P: 0.02% or less)
P is an impurity element and deteriorates toughness. Thus, the amount of P is necessarily decreased as much as possible. However, as a range in which the adverse effect on toughness is allowable, the amount of P is limited to 0.02% or less. In order to further improve the toughness, the upper limit of the amount of P may be 0.015%, 0.01%, 0.008%, or 0.006%. The lower limit of the amount of P does not need to be limited and the lower limit of the amount of P is 0%.
(S: 0.01% or less)
S is an impurity element and deteriorates toughness. Thus, it is preferable that the amount of S be decreased as much as possible. As a range in which the adverse effect on toughness is allowable, the amount of S is limited to 0.01% or less. In order to further improve the toughness, the upper limit of the amount of S may be 0.008%, 0.006%, 0.004%, or 0.003%. The lower limit of the amount of S does not need to be limited and the lower limit of the amount of S is 0%.
(Al: 0.003% to 0.050%)
Al is a deoxidizing element and is effective in increasing cleanliness similar to Si and Mn. In order to exert the effect, 0.003% or more of Al is contained. On the other hand, when the amount of Al is more than 0.050%, nitrides and oxides are formed and the toughness of the weld metal is deteriorated. Therefore, 0.050% is set as an upper limit. In addition, the lower limit of the amount of Al may be 0.005%, 0.007%, 0.009%, or 0.011% to obtain a sufficient effect of improving the toughness of the weld metal, and the upper limit of the amount of Al may be 0.040%, 0.035%, 0.030%, or 0.025% to suppress the formation of oxides.
(Ni: 6.0% to 16.0%)
Ni is a unique element capable of improving toughness by solid solution toughening (an action of increasing toughness by solid solution) irrespective of a structure and composition and is an element particularly required for securing low temperature toughness at −196° C. In order to obtain this effect, it is necessary to set the amount of Ni to 6.0% or more. On the other hand, when the amount of Ni is more than 16.0%, the effect thereof is saturated and further welding material costs increase excessively, and thus, the aforementioned amount of Ni is not preferable. The upper limit of the amount of Ni may be limited to 14% or 12%. In order to stably secure the low temperature toughness, the lower limit of the amount of Ni may be 6.5%, 7.0%, or 7.5%, or 8.0%.
In addition, Ni may be added to the weld metal mainly from the outer steel sheath. A metal power added as a flux has a thin oxide layer and the layer is an oxygen source of the weld metal. When the outer steel sheath of mild steel is used, it is necessary to add a large amount of metal powder as a flux for the addition of Ni, and oxygen in the weld metal increases due to the metal powder. In order to suppress an increase of oxygen and improve the toughness, Ni may be contained mainly in the outer steel sheath. Therefore, the amount of Ni contained in the outer steel sheath may be 6.0% or more, by mass %, with respect to the mass of the outer steel sheath. The upper limit of the amount of Ni in the outer steel sheath does not need to be particularly limited. However, the upper limit of the amount of Ni in the outer steel sheath may be 18% so that the amount of Ni is 16% or less with respect to the total mass of the wire. The upper limit of the amount of Ni in the outer steel sheath may be 17% or 16% as required.
Since a melting point of a Ni alloy is lower than a melting point of mild steel, the difference between melting points of the outer steel sheath and the flux increases when a Ni alloy is used in the outer steel sheath. Accordingly, the flux is stabilized as a core and thus droplet transfer is more stabilized. For relative comparison, the outer steel sheath made of a Ni alloy has a small amount of oxygen in the weld metal and high low temperature toughness.
In the present invention, for the following purposes, one or more of each element of Cu, Cr, Mo, V, Ti, Nb, B, Mg, and REM can be contained as an optional element.
(Cu: 0% to 0.5%)
Cu has an effect of increasing the strength of the weld metal when Cu is included in plating of the outer steel sheath of the wire or flux of the wire as a single body or an alloy. Although the lower limit of the amount of Cu is 0%, Cu may be contained. If the amount of Cu is more than 0.5%, the toughness is deteriorated. Thus, the amount of Cu is 0.5% or less. In order to improve the toughness, the upper limit of the amount of Cu may be 0.3%, 0.2%, or 0.1%. Here, the amount of Cu includes a part contained in the outer steel sheath and the flux as well as a part of Cu plating if the Cu plating is plated on the surface of the wire. In order to obtain the effect by containing, the lower limit of the amount of Cu may be 0.01%.
(Cr: 0% to 0.5%)
Cr is an effective element for increasing the strength of the weld metal. The lower limit of the amount of Cr is 0%. If Cr is contained, when the amount of Cr is more than 0.5%, the toughness is deteriorated. Thus, the amount of Cr is 0.5% or less. In order to improve the toughness, the upper limit of the amount of Cr may be 0.3%, 0.2%, or 0.1%. In order to obtain the effect by containing, the lower limit of the amount of Cr may be 0.01%.
(Mo: 0% to 0.5%)
Mo is an effective element in increasing the strength of the weld metal by precipitation strengthening. The lower limit of the amount of Mo is 0%. If the amount of Mo when being added is more than 0.5%, the toughness is deteriorated. Thus, the amount of Mo is 0.5% or less. In order to improve the toughness, the upper limit of the amount of Mo may be 0.3%, 0.2%, or 0.1%. In order to obtain the effect by containing, the lower limit of the amount of Mo may be 0.01%.
(V: 0% to 0.2%)
V is an effective element in increasing the strength of the weld metal by precipitation strengthening. The lower limit of the amount of V is 0%. If the amount of V when being added is more than 0.2%, the toughness is deteriorated. Thus, the amount of V when being contained is 0.2% or less. In order to improve the toughness, the upper limit of the amount of V may be 0.15%, 0.1%, or 0.05%. In order to obtain the effect by containing, the lower limit of the amount of V may be 0.01%.
(Ti: 0% to 0.1%)
Ti is effective in alleviating the adverse effect of solid-soluted N on toughness by fixing the solid-soluted N. Further, Ti is effectively used as a deoxidizing element and has an effect of reducing the amount of O in the weld metal. The lower limit of the amount of Ti is 0%. If the amount of Ti when being added is more than 0.1% and the amount of Ti is excessive, carbides are formed and the toughness is deteriorated. Thus, the amount of Ti when being contained is 0.1% or less. In order to improve the toughness, the upper limit of the amount of Ti may be 0.06%, 0.04%, or 0.02%. In order to obtain the effect by containing, the lower limit of the amount of Ti may be 0.005%.
(Nb: 0% to 0.1%)
Nb is effective in increasing the strength of the weld metal by precipitation strengthening. The lower limit of the amount of Nb is 0%. If the amount of Nb when being added is more than 0.1%, coarse precipitates are formed in the weld metal and the toughness is deteriorated. Thus, the amount of Nb when being contained is 0.1% or less. In order to improve the toughness, the upper limit of the amount of Ti may be 0.06%, 0.04%, or 0.02%. In order to obtain the effect by containing, the lower limit of the amount of Nb may be 0.002%.
(B: 0% to 0.01%)
When an appropriate amount of B is contained in the weld metal, B has an effect of alleviating the adverse effect of the solid-soluted N on toughness by being combined with solid-soluted N to form BN. The lower limit of the amount of B is 0%. If the amount of B when being added is more than 0.01%, the amount of B is excessive in the weld metal and the excess B forms coarse BN and B-compounds such as Fe23(C,B)6, which deteriorates toughness. Thus, the amount of B when being contained is 0.01% or less. In order to improve the toughness, the upper limit of the amount of B may be 0.006%, 0.004%, or 0.002%. In order to obtain the effect by containing, the lower limit of the amount of B may be 0.0003%.
(Mg: 0% to 0.6%)
Mg is a strongly deoxidizing element and has an effect of improving toughness by reducing the amount of oxygen in the weld metal. The lower limit of the amount of Mg is 0%. If the amount of Mg when being added is more than 0.6%, the amount of spatter increases and welding efficiency is deteriorated. Thus, the amount of Mg when being contained is 0.6% or less. In order to improve the welding efficiency, the upper limit of the amount of Mg may be 0.4%, 0.2% or 0.1%. In order to obtain the effect by containing, the lower limit of the amount of Mg may be 0.05%.
(REM: 0% to 0.0500%)
When an excessive amount of REM is contained, spattering is violent and welding efficiency is deteriorated. Therefore, the lower limit of the amount of REM is 0%. An effective amount of REM in which the amount of spatter is reduced and arcs are stable when being added is 0.0500% or less. In addition, in order to contribute to spattering reduction and stable arcs, the upper limit of the amount of REM may be 0.0300%, 0.0200%, 0.0100%, 0.0050%, or 0.0010%.
In the flux-cored wire of the embodiment, each element is contained as an alloy composition or a metal deoxidizing composition as described above. However, in order to secure the low temperature toughness at −196° C., it is necessary to set a total amount SM of Si and Mn shown in the following Table 1 to be 0.3% to 1.0%.

SM=[Si]+[Mn]  (Expression 1)

In the expression, elements noted in brackets express amounts (mass %) of the elements, respectively.
The flux-cored wire of the embodiment enables stable welding during the gas-shielded arc welding in which pure Ar or pure He is used as a shielding gas or a mixed gas in which a ratio of O2 or CO2 in Ar or He is less than 2 volume % is used as a shielding gas. However, a thin oxide layer is present around the metal powder filled in the flux-cored wire and oxygen is introduced into the weld metal although the amount of oxygen is small.
At this time, when the amount of Si and Mn which improves the cleanliness of the weld metal is not sufficient, weld defects such as a blowhole is generated in the weld metal due to oxygen from the wire. In order to prevent such weld defects, it is necessary to contain Si and Mn such that the SM is 0.3% or more. On the other hand, in the weld metal containing 6% to 16% of Ni, Si and Mn are easily micro-segregated and remarkable embrittlement is caused in the segregated portion. When the SM is 1.0% or less, embrittlement is allowable in the segregated portion and thus 1.0% is set as an upper limit. In order to more reliably prevent the weld defects, the lower limit of the SM may be 0.35% or 0.4%.
The experiments by which such findings are obtained are shown in FIGS. 1 and 2. The entire outer steel sheath of the flux-cored wire used in FIG. 1 is made of mild steel, and the entire outer steel sheath of the flux-cored wire used in FIG. 2 is made of Ni-containing steel. FIGS. 1 and 2 show relationships between Charpy absorbed energy at −196° C. and SM of a wire obtained using a test piece that is prepared from a weld metal obtained by preparing flux-cored wires which satisfy the requirements of the present invention except that the SM value is different, and performing welding using the wires in the same manner as in examples which will be described later.
As seen from FIG. 1, in the wire in which Si and Mn are added such that the SM is 0.3 to 1.0, the Charpy absorbed energy at −196° C. was 50 J or more. As seen from FIG. 2, in the wire in which Si and Mn are added such that the SM is 0.3 to 1.0, the Charpy absorbed energy at −196° C. was 69 J or more. When the entire outer steel sheath is made of mild steel, in order to stably secure an absorbed energy of 50 J or more, the upper limit of the SM may be 0.9%, 0.8%, 0.75%, or 0.70%. When the entire outer steel sheath is made of Ni-containing steel, in order to stably secure an absorbed energy of 69 J or more, the upper limit of the SM may be 0.9%, 0.8%, 0.75%, or 0.70%.
(Carbon equivalent Ceq: 0.250% to 0.525%)
Further, in the flux-cored wire of the embodiment, the amounts of C, Si, Mn, Ni, Cr, Mo, and V are adjusted so that a carbon equivalent Ceq, expressed by the following expression 2 and defined by the Japan Welding Engineering Society (WES), is 0.250% to 0.525%.

Ceq=[C]+[Si]/24+[Mn]/6+[Ni]/40+[Cr]/5+[Mo]/4+[V]/14   (Expression 2)

In the expression, elements noted in brackets express amounts of the elements, by mass %, respectively.
Although the tensile strength of the weld metal is increased as the Ceq value increases, the toughness is deteriorated and the weld cracking parameter is increased as the Ceq value increases. Thus, a countermeasure for preventing cold cracking is required. When the Ceq value is less than 0.250%, a target strength (tensile strength) of the weld metal of 660 MPa or more cannot be satisfied. On the other hand, when the Ceq value is more than 0.525%, the tensile strength of the weld metal becomes excessive and the toughness of the weld metal is deteriorated. Therefore, the range of the Ceq is from 0.250% to 0.525%. In order to stably secure the strength, the lower limit of the Ceq value may be 0.290%, 0.330%, or 0.370%. In order to improve the toughness, the upper limit of the Ceq may be 0.490%, 0.460%, or 0.430%.
Here, the amount of the elements contained in the wire as the above alloy composition and metal deoxidizing composition does not include the amount of the elements when the elements are contained as a metal fluoride, a metal oxide, and a metal carbonate.
In addition, these elements are not necessarily pure substances (impurities may be contained) and there is no problem even when the elements may be contained in the form of alloys such as Fe—Mn and Cu—Ni. Further, even when these elements are contained in the outer steel sheath, or as the flux, the same effect is exerted. Thus, the elements may be contained in any of the outer steel sheath and the flux.
Subsequently, a flux composition which is inserted into the outer steel sheath of the wire will be described.
(Total amount α of metal fluoride including CaF2 as main composition: 2.0% to 7.0%)
In the related art, in the gas-shielded arc welding using an inert gas, a thermal pinch force and electromagnetic pinch force generated during welding are small, and thus, a droplet formed at the tip end of the wire does not drop from the wire and the molten portion extends like a liquid column. The molten portion is swayed like a whip by affection of a plasma airflow and magnetic blow. Then, the state of arcs becomes very unstable and welding is not possible.
In the embodiment, when a metal fluoride including CaF2 as a main composition was used as a flux composition for the flux-cored wire, stable welding was possible even in gas-shielded arc welding using an inert gas. The outer steel sheath melts under the arcs. However, since the metal fluoride has a low electric conductivity, the flux inside the wire does not melt completely and remains as a core, and the core of the flux is introduced straightly into a molten pool without swaying like a whip. At this time, the molten outer steel sheath is moved to the molten pool along the core of the flux, and thus, stable welding is possible.
In order to make stable welding possible even in the gas-shielded arc welding using an inert gas, it is necessary to contain the metal fluoride including CaF2 such that when a total amount thereof is defined as a, the α is 2.0% or more and a ratio ([CaF2]/α) of the amount of [CaF2] with respect to the α is 0.90% or more. The larger the amount of CaF2 is, the more preferable it is. The lower limit of the ratio may be 0.93, 0.96, 0.98, or 0.99. There is no problem when the ratio is 1.0 and only CaF2 is used.
When the total amount α of the metal fluoride is less than 2.0%, the core of the flux remains insufficient during the welding and thus welding is unstable. On the other hand, when the total amount α of the metal fluoride is more than 7.0%, excessive welding fume is generated and welding is unstable. Thus, the above total amount is not preferable.
In order to secure more stable weldability even in the gas-shielded arc welding using an inert gas, the lower limit of the total amount α of the metal fluoride may be 2.2%, 2.4%, 2.6%, 2.8%, 3.0%, 3.2%, or 3.4%, and the upper limit of the total amount α of the metal fluoride may be 6.5%, 6.0%, 5.5%, or 5.0%.
As the metal fluoride, in addition to CaF2, one or more of BaF2, SrF2, MgF2, and LiF can be contained as required. However, from the viewpoint of securing arc stability and suppressing spattering, a ratio of the amount of CaF2 with respect to a total amount of CaF2, BaF2, SrF2, MgF2, and LiF has to be 0.90 or more. When the ratio is less than 0.90, the arc stability is deteriorated. The higher the ratio of CaF2 is, the more preferable it is. The ratio may be 0.93% or more, 0.96% or more, 0.98% or more, or 0.99% or more. There is no problem when the ratio of CaF2 is 100%.
In addition to the above-described actions, the metal fluoride also has an action of reducing the amount of diffusible hydrogen in the weld metal.
The weld metal containing 6% to 16% of Ni has a very hard martensite structure. Therefore, preheating is required for preventing cold cracking. However, since the metal fluoride can reduce the amount of diffusible hydrogen in the weld metal, the metal fluoride makes it possible that welding is performed with omitting or simplifying preheating required to prevent cold cracking.
The fact that the metal fluoride has an action of reducing the amount of diffusible hydrogen is known by a covered arc electrode. However, an example in which a diffusible hydrogen reduction in the flux-cored wire is investigated in detail does not exist. In the embodiment, the most suitable form for reducing the diffusible hydrogen has been found in consideration of other flux compositions, mechanical properties of the weld metal, welding workability, or the like.
The reason why the metal fluoride reduces the diffusible hydrogen is that the metal fluoride is decomposed by welding arcs, the generated fluorine is bonded with hydrogen and dispersed in the air as a HF gas, or hydrogen is fixed in the weld metal as a HF gas without any change.
(Ti oxide: 0% to 0.4%)
In order to improve low temperature toughness by reducing the amount of oxygen in the weld metal, it is preferable to reduce the amount of TiO2, included as Ti oxide, as much as possible. Therefore, the lower limit of TiO2 is 0%. On the other hand, in order to obtain good bead formability, slag peelability, and arc stability, it is preferable to add TiO2. Therefore, the lower limit of the amount of TiO2 may be 0.05%, 0.1%, 0.13%, 0.16%, or 0.19%. When the amount of TiO2 is more than 0.4%, oxygen included in TiO2 is introduced into the molten pool and thus the amount of oxygen in the weld metal increases and the absorbed energy at ductile fracture decreases. Thus, the upper limit is 0.4%. The upper limit of the amount of TiO2 may be 0.35%, 0.31%, 0.27%, or 0.24% as required. When the low temperature toughness is emphasized, the upper limit of the amount of TiO2 may be 0.2%, 0.15%, 0.12%, or 0.09%.
(Si oxide: 0.2% to 0.5%)
SiO2, included as Si oxide, is necessary to arrange the form of slag and make slag peeling easy after welding. In order to exert the effect, the amount of SiO2 is necessarily 0.2% or more. The lower limit of the amount of SiO2 may be 0.23%, 0.26%, or 0.29%. However, when the amount of SiO2 contained is more than 0.5%, oxygen included in the SiO2 is introduced into the molten pool and the amount of oxygen in the weld metal increases and the absorbed energy at ductile fracture decreases. Therefore, 0.5% is set as an upper limit. The upper limit of the amount of SiO2 may be 0.45%, 0.39%, 0.37%, or 0.34%.
(Total amount of metal oxide: 0.2% to 0.9%)
In the flux-cored wire of the embodiment, as a slag forming agent one or more metal oxides such as a Ti oxide, a Si oxide, a Mg oxide, an Al oxide, a Zr oxide, and a Ca oxide, for example, TiO2, SiO2, MgO, Al2O3, ZrO2, and CaO, are included. These metal oxides are included to maintain a good weld bead shape. In order to obtain the appropriate effect of the metal oxides, when a total amount of the metal oxides is defined as β, it is necessary to set the lower limit of the β to be 0.2%. However, when the total amount β of the metal oxides is more than 0.9%, the amount of oxygen in the weld metal increases and the toughness is deteriorated. Thus, the above total amount is not preferable.
The total amount of these metal oxides includes, in addition to the total amount of TiO2, SiO2, MgO, Al2O3, ZrO2, and CaO, an amount of a metal oxide included in a binder or the like which is used in flux granulation. In order to reliably obtain the effect of these metal oxides, the lower limit of the total content of the metal oxides may be 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, or 0.5%. Further, in order to suppress deterioration in the toughness of the weld metal due to the containing of the metal oxides as much as possible, the upper limit of the total amount 13 of the metal oxides may be 0.8%, 0.7%, or 0.6%.
(Arc stabilizer: 0% to 0.50%)
Additionally, an arc stabilizer may be further contained in the flux. As the arc stabilizer, there are oxides or fluorides of Na or K (for example, Na2O, NaF, K2O, KF, K2SiF6, and K2ZrF6) or the like, and the total amount thereof is 0% to 0.50%. Since the arc stabilizer may not be necessarily contained, the lower limit of the total amount of oxides or fluorides of Na or K is 0%. In addition, since arcs become stronger and the amount of spatter increases, the upper limit is 0.50%. The oxides and fluorides as the arc stabilizer described as an example herein may not include the above-described metal oxides functioning as the slag forming agent and metal fluorides used to reduce the amount of diffusible hydrogen. When the amount of the oxides and fluorides of Na and K is large, arcs become stronger and the amount of spatter increases. Thus, the total amount of the compounds may be limited to 0.40% or less, 0.30% or less, or less than 0.20%, 0.10% or less, as required.
In addition to the amount of each of the above-described metal oxides and metal fluorides, it is necessary that a ratio (α/β) of the total amount α of the metal fluoride with respect to the total amount β of the metal oxide expressed by mass % satisfy 3.0 or more and 15.0 or less.
When the value of α/β is less than 3.0, the amount of oxygen in the weld metal increases, which causes a decrease in the absorbed energy. When the value of α/β is more than 15.0, arcs easily become unstable in the gas-shielded arc welding using an inert gas. As required, the lower limit of α/β may be 3.5 or 4.0, and the upper limit thereof may be 14.0, 13.0, or 12.0. In addition, it is important to control the value of the ratio α/β to obtain the effect of reducing the amount of diffusible hydrogen, and the effect of reducing the amount of diffusible hydrogen can be obtained as long as the value is within the range of the embodiment.
(Ca oxide: less than 0.20%)
In the embodiment, the amount of CaO, included as Ca oxide, contained in the flux is limited. CaO is contained as a raw material for the flux in some cases. Even in this case, the amount of CaO is limited to less than 0.20%, by mass %, with respect to the total mass of the flux-cored wire. When the amount of CaO is limited to less than 0.20%, the effects of the present invention can be obtained. That is, the raw material for the flux is preferably selected such that the upper limit of the amount of CaO is less than 0.20%. As required, the upper limit of the amount of CaO may be limited to less than 0.18%, less than 0.15%, less than 0.12%, less than 0.10%, less than 0.08%, less than 0.06%, or less than 0.04%. The lower limit of the amount of CaO may be 0%. Due to the selection of the raw material for the flux, the lower limit of the amount of CaO may be 0.01% or 0.005%.
Since CaO is changed to CaOH which is a compound including hydrogen by being exposed to the air, the amount of diffusible hydrogen in the weld metal is increased. The experiments from which such finds are obtained are shown in FIGS. 3 and 4.
FIG. 3 shows a relationship between the amount of CaO in flux-cored wires and the amount of diffusible hydrogen obtained by preparing flux-cored wires which satisfy the requirements of the present invention except that the value of CaO is different and which have the entire outer steel sheath being made of mild steel, performing welding using the wires, and measuring an amount of diffusible hydrogen in obtained weld metals in the same manner as in examples which will be described later.
FIG. 4 shows a relationship between the amount of CaO in flux-cored wires and the amount of diffusible hydrogen obtained by preparing flux-cored wires which satisfy the requirements of the present invention except that the value of CaO is different and which have the entire outer steel sheath being made of Ni-containing steel, performing welding using the wires, and measuring an amount of diffusible hydrogen in obtained weld metals in the same manner as in examples which will be described later.
From FIGS. 3 and 4, as the amount of CaO increases, the amount of diffusible hydrogen in the weld metal increases. Until the amount of CaO reaches 0.20%, an amount of diffusible hydrogen of 1.5 ml/100 g or less can be obtained. The amount of
CaO is less than 0.20%, since the effect of reduction of preheating can be obtained when the amount of diffusible hydrogen is 1.5 ml/100 g or less. That is, the raw material for the flux is selected such that the ranges are satisfied.
(Metal carbonate: less than 0.60%)
For the purpose of an action of stabilizing arcs and increasing arc convergence, the flux-cored wire of the embodiment may contain one or more metal carbonates of CaCO3, BaCO3, SrCO3, MgCO3, and Li2CO3. When a total amount of metal carbonates is 0.60% or more, arc convergence becomes excessively stronger and the amount of spatter generated increases. Therefore, the total amount of the metal carbonates is less than 0.60%. As required, the total amount may be 0.40% or less, 0.20% or less, 0.10% or less, or 0.07% or less. These metal carbonates are not necessarily contained in the wire and the lower limit thereof is 0%.
(Iron powder: less than 5%)
An iron powder is contained in the flux-cored wire to adjust a flux filling rate in the flux-cored wire or improve deposition efficiency in some cases as required. However, since the surface layer of the iron powder is oxidized, the amount of oxygen in the weld metal may increase and the toughness may be deteriorated when the flux contains excessive ion powder. Accordingly, the iron powder may not be contained. That is, the lower limit thereof is 0%. When the iron powder is contained to adjust the filling rate, the upper limit of the amount of the iron powder is less than 5% to secure the toughness of the weld metal.
The reason why the chemical composition of the flux-cored wire of the embodiment is limited has been described above. Other alloy chemical compositions as a remainder are iron and impurities. The iron composition includes iron of the outer steel sheath, an iron powder included in the flux, and iron in alloy compositions. In addition, a remainder including iron as a main composition may contain impurities entering during the manufacturing process in a range not inhibiting the characteristics of the present invention.
(Filling rate: 5.0% to 30.0%)
Since a hollow space inside the outer steel sheath is filled with the flux, there is an upper limit in a filling rate. The upper limit of the filling rate varies depending on the thickness of the outer steel sheath. However, a preferable value of upper limit of the filling rate is 30.0% to stably add the flux. The upper limit of the filling rate may be 25.0%, 20.0%, or 15.0%. In addition, regarding the lower limit of the filling rate, when the filling rate is too low, the flux filling the inside of the outer steel sheath does not have a frictional force with the outer steel sheath and can be moved and thus, there is a concern of a dense flux. Therefore, the lower limit of the filling rate is preferably 5%.
Subsequently, the shape of the flux-cored wire will be described.
The flux-cored wire can be roughly divided into a seamless wire in which a slit-shaped gap does not exist in the outer steel sheath, and a wire with a seam in which a slit-shaped gap exists in the outer steel sheath.
In the present invention, any cross-sectional structure can be employed. However, in order to prevent cold cracking of the weld metal, it is preferable to form a (seamless) wire in which a slit-shaped gap does not exist.
In addition, in order to improve the feedability of the wire during the welding, a lubricant can be applied onto the surface of the wire. As the lubricant for a weld wire, various kinds of lubricants can be used. However, in order to prevent the cold cracking of the weld metal, a perfluoropolyether oil (PFPE oil) is preferably used.
Hydrogen penetrated into the weld portion during the welding diffuses into the weld metal and steel, is accumulated in a stress concentration portion, and causes cold cracking. Examples of the hydrogen source include moisture that the welding material holds, moisture entering from the air, and rust or scales adhering onto the surface of the steel. In the welding in which the cleanliness of the weld portion and conditions for gas-shielding are sufficiently managed, hydrogen contained mainly as moisture in the wire is a major cause for diffusible hydrogen present in the weld joint.
Therefore, it is preferable to suppress penetration of hydrogen in the air from the outer steel sheath to the flux in a period from the manufacturing of the wire to the use of the wire by using a (seamless) tube in which a slit-shaped gap does not exist for the outer steel sheath.
When a tube (with a seam) in which a slit-shaped gap exists is used for the outer steel sheath, the moisture in the air easily penetrates into the flux from the slit-shaped gap (seam portion) on the outer steel sheath and in this state, the penetration of the hydrogen source such as moisture cannot be prevented. Accordingly, when the period from the manufacturing of the wire to the use of the wire is long, it is preferable that the entire wire be vacuum-packed or stored in a container in which the wire can be stored in a dried state.
In the present invention, the tensile strength of the weld metal has the same level as that of high strength steel having a tensile strength of 660 MPa to 900 MPa. The tensile strength of the weld metal can be measured in such a manner that a tensile test defined in Japanese Industrial Standards JIS Z 3111-2005 is performed on the weld metal of the weld joint prepared using the flux-cored wire. Further, a good correlation between hardness and tensile strength has been known. The tensile strength of the weld metal may be obtained by measuring the hardness of the weld metal of the weld joint and converting the hardness into the tensile strength using the correlation. The lower limit of the tensile strength of the weld metal may be limited to 685 MPa and the upper limit thereof may be limited to 830 MPa as required.
The flux-cored wire used in the embodiment can be manufactured in the same manufacturing steps as in a method for manufacturing a typical flux-cored wire.
That is, first, a steel strip which becomes the outer steel sheath and a flux in which a metal fluoride, an alloy composition, a metal oxide, a metal carbonate, and an arc stabilizer are blended so as to have a predetermined amount are prepared. While being fed in the longitudinal direction, a steel strip is formed into an open tube (U-shaped tube) by a forming roll to be set as an outer steel sheath, the flux is supplied from an opening portion of the open tube in the middle of the forming, and edge surfaces facing each other at the opening portion is subjected to butt seam welding by electric sewing welding, laser beam welding, or TIG welding. The tube having no gap obtained by the welding is wire-drawn and is subjected to annealing in the middle of the wire-drawing or after the completion of the wire-drawing so as to obtain a (seamless) wire having no slit-shaped gap and a predetermined wire diameter and including the flux to fill the inside of the outer steel sheath. In addition, a wire (with the seam) in which a slit-shaped gap exists can be obtained by supplying the flux from the opening portion of the open tube, forming a tube having a gap on which seam welding is not performed, and wire-drawing the tube.
Here, the shape of the seamless wire, particularly, the cross sectional structure thereof will be described using FIGS. 5A to 5C. FIGS. 5A to 5C are views showing cross sections of the wires.
A cross section of a wire which is prepared by butt seam welding and has no slit-shaped gap can be seen as in FIG. 5A. When this cross section is polished and etched, a welding trace is observed. However, when the wire is not etched, the welding trace is not observed. Therefore, the wire is called a seamless wire in some cases. In “1000 numbers of Q and A of Bonding and Joining Technology”, compiled by the editorial committee of 1000 numbers of Q and A of Bonding and Joining Technology, and published by Industrial Technology Center Incorporated, p. 564, the wire is described as a seamless type. Further, even when a gap exists as shown in FIGS. 5B and 5C, the wire is butted and brazed, or caulked and brazed and then a wire in which a slit-shaped gap does not exist can be obtained. In FIGS. 5B and 5C, the wire on which brazing is not performed is a wire in which a slit-shaped gap exists as shown in the drawings.
The flux-cored wire of the embodiment may be used for performing gas-shielded arc welding on Ni-based steel for low temperature use including 5.5% to 5.9% of Ni. Steel having an amount of Ni of 5.5% to 5.9%, a thickness of 6 mm or more and 100 mm, a tensile strength of 660 MPa to 900 MPa, and a Charpy absorbed energy at −196° C. of 41 J or more or 50 J or more is used for an LNG storage tank. When the steel is subjected to welding, the flux-cored wire of the embodiment can be used to manufacture a weld joint. In this case, a person having substantial experience in welding for LNG tank may manufacture weld joint having good characteristics only with taking care of selection of shielding gas.
Pure Ar gas or Pure He gas may be used for the shielding gas used to weld. In addition, even if the pure Ar gas or the pure He gas are mixed with 1.5 volume % or less of O2 or 1.5 volume % or less of CO2, the effect according to the present invention can be obtained.
The experiment results obtained from such findings are shown in FIGS. 6 and 7. FIGS. 6 and 7 show results obtained by welding 9% Ni steels with a pure Ar gas, a mixed gas of Ar with O2 at various concentrations, a mixed gas of Ar with CO2 at various concentrations, a pure He gas, a mixed gas of He with O2 at various concentrations, or a mixed gas of He with CO2 at various concentrations as a shielding gas and with the flux-cored wire having the chemical composition of the embodiment and then measuring the amount of oxygen and the Charpy absorbed energy at −196° C. of the weld metals. Here, the entire outer steel sheaths of the flux-cored wires used in FIG. 6 are made of mild steel, and the entire outer steel sheaths of the flux-cored wires used in FIG. 7 are made of Ni-containing carbon steel. The amounts of Ni in the Ni-containing steels are 6% to 18%.
In FIG. 6, when a mixed gas in which O2 or CO2 was contained in the pure Ar gas or the pure He gas within a range of 1.5 volume % or less was used, the amounts of oxygen in all of the weld metals were 160 ppm or less. Further, when the amounts of oxygen in the weld metals were 160 ppm or less, Charpy absorbed energy thereof at −196° C. is 50 J or more.
In FIG. 7, when a mixed gas in which O2 or CO2 was contained in the pure Ar gas or the pure He gas within a range of 1.5 volume % or less was used, the amounts of oxygen in all of the weld metals were 80 ppm or less. In addition, when the amounts of oxygen in the weld metals were 80 ppm or less, Charpy absorbed energy thereof at −196° C. is 69 J or more.
As described above, the shielding gas used to weld is preferably pure Ar gas, pure He gas, a mixed gas of the pure Ar gas and 1.5 volume % or less of O2 or CO2, or a mixed gas of the pure He gas and 1.5 volume % or less of O2 or CO2. On the other hand, a mixed gas of the pure Ar gas and more than 1.5 volume % of O2 or CO2 or a mixed gas of the pure He gas and more than 1.5 volume % of O2 or CO2, for example, a mixed gas of the pure Ar gas and 2.5 volume % or less of O2 or CO2 or a mixed gas of the pure He gas and 2.5 volume % or less of O2 or CO2, may be used. In this case, it is important to add two or more of Al, Ti, and Mg, which are deoxidizing compositions, in the wire with high content to decrease an amount of O2 in the weld metal.
In particular, in a case in which a mixed gas of the pure Ar gas and more than 1.5 volume % of O2 or CO2 or a mixed gas of the pure He gas and more than 1.5 volume % of O2 or CO2 are used, it is preferable an amount of either one of Al, Ti, and Mg included in the wire is 70% or more of the upper limit of Al, Ti, and Mg defined in the present embodiments. For example, it is preferable to use a wire in which chemical compositions except the metal fluorides, the metal oxides, and the metal carbonates include, by mass %, with respect to the total mass of the flux-cored wire, one or more of 0.035% or more of Al, 0.07% or more of Ti, or 0.42% or more of Mg.
EXAMPLES
Hereinafter, the feasibility and effects of the present invention will be described in more detail using examples.
While being fed in the longitudinal direction, a steel strip was formed into an open tube by a forming roll and the flux was supplied from an opening portion of the open tube in the middle of the forming, and edge surfaces facing each other at the opening portion was subjected to butt seam welding to form a tube in which a slit-shaped gap did not exist. Annealing was applied to the tubulated wire in the middle of the wire-drawing to prepare a flux-cored wire having a final wire diameter of φ 1.2 mm. After the wire was prepared, a lubricant was applied onto the surface of the wire.
As an outer steel sheath (hoop), an outer steel sheath made of mild steel including C: 0.003%, Si: 0.03%, Mn: 0.11%, P: 0.006%, S: 0.003%, Al: 0.003%, and a remainder consisting of Fe and impurities, or an outer steel sheath made of Ni-containing steel shown in Table 1 was used. Here, all of % means mass % with respect to a total mass of the outer steel sheath.
In Tables 2-1, 2-3, 2-5, 2-7, 2-9, 2-11, 2-13, and 2-15, a plant oil was applied to all wires without a description of “PFPE oil applied”. In addition, some of the wires were formed into tubes having a slit-shaped gap on which seam welding was not performed, and wire-drawn to prepare flux-cored wires having a wire diameter of φ 1.2 mm. In a case of a wire in which a slit-shaped gap existed, the entire wire was stored in a container in which the wire was able to be vacuum-packaged and stored in a dried state until welding was performed.
The flux-cored wire was analyzed in the following manner. The flux-cored wire was divided into an outer steel sheath and a flux by extracting the flux filling the wire from the wire. The metal compositions of the outer steel sheath were measured by chemical analysis. The constituents and compositions of the flux were quantitatively evaluated by X-ray diffraction and fluorescence X-ray analysis and then were separated into slag and an alloy using a concentration method such as flotation concentration or magnetic concentration, and each of the slag and alloy was analyzed by chemical analysis or gas analysis.
The chemical compositions of the prepared flux-cored wires are shown in Tables 2-1 to 2-16 and 3-1 to 3-16. In addition, in Tables 3-9, 3-11, 3-13, and 3-15, numbers of the hoop materials in Table 1 used for the outer steel sheath of the wire are also shown. The chemical compositions of the flux-cored wires shown in Tables 2-1 to 2-16 and 3-1 to 3-16 are results obtained by analyzing the wires by the above-described analyzing methods. The term “mass %” in Tables 2-1 to 2-16 and 3-1 to 3-16 means mass % with respect to a total mass of the wire (including the outer steel sheath and the flux). For example, Ni in Tables 3-1, 3-3, 3-5, and 3-7 is not contained in the outer steel sheath but contained completely as a Ni powder.
Using the flux-cored wires shown in Tables 2-1 to 2-16 and 3-1 to 3-16, the mechanical properties of the weld metal according to JIS Z 3111 (2005) were evaluated. That is, a method as shown in FIG. 8 (the symbol of the test plate 1.3) was used. A steel plate 1 (base metal number: P2) having a thickness of 20 mm shown in Table 6 was butted at a groove angle of 20° with a root opening of 16 mm, and using a backing metal 2. Weld bead is indicated by a symbol 3 in the drawing. As the steel plate 1 and the backing metal 2, SM 490 A (JIS G 3106) was used. Buttering with two or more layers and with 3 mm or more of excess weld metal was performed on the groove face of the steel plate 1 and the surface of the backing metal 2 using the flux-cored wire to be subjected to a test. Then, welding was performed with the first layer and the second layer being one or two passes the third layer to the last layer being two or three passes to prepare a test body. The welding conditions are shown in Tables 4-1 to 4-7 (the composition of the shielding gas is expressed by volume %). The welding conditions of the flux-cored wire using an outer steel sheath made of mild steel in Tables 2-1 to 2-8 and 3-1 to 3-8 are shown in Tables 4-1 to 4-4. As seen from Tables 4-1 to 4-4, welding was performed under the conditions of a current value of 280 A, a voltage value of 25V, a welding rate of 30 cm/min, an interpass temperature of 150° C. or less, and a flow rate of 25 l/min using any one of a pure Ar gas, a mixed gas of Ar with O2 or CO2, a pure He gas, and a mixed gas of He with O2 or CO2 as a shielding gas. The welding conditions of the flux-cored wires using an outer steel sheath made of Ni-containing steel in Tables 2-9 to 2-16 and 3-9 to 3-16 are shown in Tables 4-5 to 4-7. As seen from Tables 4-5 to 4-7, welding was performed under the conditions of a current value of 280 A, a voltage value of 25V, a welding rate of 30 cm/min, an interpass temperature of 150° C. or less, and a flow rate of 25 l/min using any one of a pure Ar gas, a mixed gas of Ar with O2 or CO2, a pure He gas, and a mixed gas of He with O2 or CO2 as a shielding gas.
The tensile strength and the Charpy absorbed energy of the weld metals were measured by collecting a A0 test piece (rod) 5 for tensile test according to JIS Z 3111 (2005) (having a diameter of 10 mm) and a Charpy impact test piece 4 (having a 2 mm V-notch) from the prepared test body as shown in FIG. 8 as a mechanical test piece and performing mechanical property tests each of the test pieces. The results obtained by measuring and evaluating the mechanical properties obtained when the flux-cored wire using an outer steel sheath made of mild steel is used are shown in Tables 5-1 to 5-4, and the results obtained by measuring and evaluating the mechanical properties obtained when the flux-cored wire using an outer steel sheath made of Ni-containing steel is used are shown in Tables 5-5 to 5-8.
As seen from FIG. 6, as the evaluation of the mechanical properties when the flux-cored wire in which the outer steel sheath was made of mild steel was used, the test piece having the tensile strength of 660 MPa to 900 MPa and the toughness in which absorbed energy was 50 J or more in the Charpy impact test at −196° C. was accepted.
As seen from FIG. 7, as the evaluation of the mechanical properties when the flux-cored wire in which the outer steel sheath was made of Ni-containing steel was used, the test piece having the tensile strength of 660 MPa to 900 MPa and the toughness in which the absorbed energy was 69 J or more in the Charpy impact test at −196° C. was accepted.
In addition, a test piece was collected from each of the obtained weld metals to measure an amount of oxygen in the weld metal. The amount of oxygen in the weld metal was measured by impulse heating furnace-inert gas melting infrared absorbing method. The measured amount of oxygen in each of the weld metals was shown in Tables 5-1 to 5-8.
In the wire of the present invention, the toughness was improved by reducing the amount of oxygen in the weld metal. Regarding the flux-cored wire in which the entire outer steel sheath was made of mild steel was used, the Charpy absorbed energy at −196° C. was able to be secured in the weld metal including an amount of oxygen of 160 ppm or less. Further, regarding the flux-cored wire in which the entire outer steel sheath was made of Ni-containing steel was used, the Charpy absorbed energy at −196° C. was able to be secured in the weld metal including an amount of oxygen of 80 ppm or less.
Next, regarding the flux-cored wire in which both the tensile strength and the Charpy absorbed energy at −196° C. were acceptable in the evaluation results of Tables 5-1 to 5-8, the cold cracking resistance was evaluated. The cold cracking resistance was evaluated by the measurement of the amount of diffusible hydrogen and a y-groove weld cracking test. However, regarding the wire number B39 in Table 5-4, the amount of a Ca oxide was large and thus the amount of diffusible hydrogen was measured.
The amount of diffusible hydrogen was measured by gas chromatography according to JIS Z 3118 (method for measuring the amount of hydrogen in the steel weld portion) with the same welding conditions as in the mechanical property test. The measurement results of the amount of the diffusible hydrogen are shown in Tables 5-1 to 5-8.
The y-groove weld cracking test was performed using a steel plate (base metal number: P1) having a thickness of 25 mm shown in Table 6 under a predetermined atmosphere control of a temperature of 0° C. and a humidity of 60% by a method according to JIS Z 3158 (y-groove weld cracking test) with the welding conditions of Tables 4-1 to 4-7.
The obtained y-groove weld cracking test results are shown in Tables 5-1 to 5-8. When the amount of diffusible hydrogen was 1.5 ml/100 g or less, very high cold cracking resistance was demonstrated, since there was no cross-sectional cracking (i.e. no cross-sectional cracking was occurred) in all of the cross sections during y-groove weld cracking test even if the test temperature was 0° C. and preheating was not performed.
As shown in the test results of Tables 5-1, 5-2, 5-5, and 5-6, the tensile strength, toughness, and cold cracking resistance of the samples made with wires with numbers A1 to A108, which were examples of the present invention, were all excellent, and the wires were acceptable. The sample regarding a wire with number A108 is an example in which a shielding gas is a mixed gas of pure Ar gas and 2.0 volume % of O2. Since Al, Ti, and Mg, which are deoxidizing compositions, were sufficiently added to the wire with number A108, an amount of O2 in the weld metal thereof was reduced and the sample regarding the wire with number A108 had excellent toughness.
On the other hand, as shown in the test results of Tables 5-3, 5-4, 5-7, and 5-8, the samples made with wires with numbers of B1 to B101, which were comparative examples, did not satisfy the requirements defined in the present invention, and thus, one or more of the tensile strength, toughness, and cold cracking resistance were not able to be satisfied and the wires were not acceptable in the total determination. The wires of the wire Nos. B34, B34, B35. B46, B47, B48, B87, B88, B98, B99, and B100 satisfied requirements according to the present invention; however, since shielding gas were inappropriate, amounts of O2 in the weld metals made with the wires were high, and thus, the toughness thereof were low.








TABLE 1








CHEMICAL COMPOSITION OF OUTER STEEL SHEATH OF WIRE


HOOP
[mass % WITH RESPECT TO TOTAL MASS OF OUTER STEEL SHEATH]














No.
C
Si
Mn
P
S
Al
Ni

















F1
0.010
0.03
0.1
0.007
0.004
0.012
6.0


F2
0.010
0.03
0.1
0.007
0.004
0.012
9.0


F3
0.010
0.03
0.1
0.007
0.004
0.012
12.5


F4
0.010
0.03
0.1
0.007
0.004
0.012
14.5


F5
0.020
0.15
0.2
0.007
0.004
0.002
12.5


F6
0.002
0.03
0.1
0.007
0.004
0.012
8.5




















TABLE 2-1











CHEMICAL COMPOSITION OF FLUX






[mass % WITH RESPECT TO TOTAL MASS OF WIRE]






METAL FLUORIDE



















FILLING





TOTAL


WIRE


RATE





AMOUNT


No.
CATEGORY
REMARKS
(%)
CaF2
BaF2
SrF2
MgF2
LiF
[α]





A1
EXAMPLE

15.7
2.0




2.0


A2
EXAMPLE

21.8
7.0




7.0


A3
EXAMPLE
APPLIED
16.4
2.8




2.8




PTFE


A4
EXAMPLE

18.7
3.7




3.7


A5
EXAMPLE

15.9
2.0




2.1


A6
EXAMPLE

19.5
6.0




6.0


A7
EXAMPLE
APPLIED
16.5
2.6




2.6




PTFE


A8
EXAMPLE

18.6
4.8




4.8


A9
EXAMPLE

16.4
3.2




3.2


A10
EXAMPLE

16.5
3.5


0.2
0.1
3.8


A11
EXAMPLE

17.0
3.0




3.0


A12
EXAMPLE

16.8
3.6




3.6


A13
EXAMPLE

16.7
4.6
0.2
0.1


4.9


A14
EXAMPLE

16.3
4.5




4.5


A15
EXAMPLE

14.7
3.0




3.0


A16
EXAMPLE

19.9
2.9

0.2
0.1

3.2


A17
EXAMPLE

17.3
4.5




4.5


A18
EXAMPLE
APPLIED
16.5
3.2

0.1


3.3




PTFE


A19
EXAMPLE

15.0
3.6




3.6


A20
EXAMPLE

14.6
3.2
0.2



3.4


A21
EXAMPLE

14.1
3.3




3.3


A22
EXAMPLE

14.3
3.6




3.6


A23
EXAMPLE

18.5
3.2


0.2

3.4


A24
EXAMPLE

19.8
4.2
0.1


0.1
4.4


A25
EXAMPLE

18.5
4.0
0.1
0.1
0.1
0.1
4.4


A26
EXAMPLE

11.0
2.8




2.8


A27
EXAMPLE

17.8
4.0




4.0














CHEMICAL COMPOSITION OF FLUX




[mass % WITH RESPECT TO TOTAL MASS OF WIRE]




METAL OXIDE























TOTAL



WIRE






AMOUNT



No.
TiO2
SiO2
MgO
Al2O3
ZrO2
CaO
[β]







A1
0.25
0.38



0.02
0.65



A2
0.22
0.25



0.02
0.49



A3
0.10
0.20



0.03
0.33



A4
0.40
0.48



0.02
0.90



A5
0.30
0.36



0.02
0.68



A6
0.10
0.30



0.02
0.42



A7
0.12
0.25



0.03
0.40



A8
0.15
0.22
0.12


0.02
0.51



A9
0.20
0.26

0.18

0.03
0.67



A10
0.15
0.25



0.03
0.43



A11
0.22
0.28

0.12

0.02
0.64



A12
0.16
0.36
0.12


0.02
0.66



A13
0.14
0.32



0.06
0.52



A14
0.34
0.34



0.02
0.70



A15
0.16
0.24
0.12
0.10

0.02
0.64



A16
0.36
0.20



0.02
0.58



A17
0.20
0.32



0.18
0.70



A18
0.12
0.32
0.20


0.02
0.66



A19
0.26
0.25

0.12

0.02
0.65



A20
0.15
0.35
0.12


0.02
0.64



A21
0.12
0.22

0.25

0.02
0.61



A22
0.31
0.39



0.02
0.72



A23
0.18
0.46



0.02
0.66



A24
0.13
0.33
0.15
0.08

0.02
0.71



A25
0.16
0.21



0.02
0.39



A26
0.22
0.34



0.05
0.61



A27
0.12
0.20
0.10
0.12

0.05
0.59










[Table 2-2]










TABLE 2-2









CHEMICAL COMPOSITION OF FLUX




[mass % WITH RESPECT TO TOTAL MASS OF WIRE]










METAL CARBONATE


















WIRE





TOTAL
IRON
ARC




No.
CaCO3
BaCO3
SrCO3
MgCO3
Li2CO3
AMOUNT
POWDER
STABILIZER
α/β
CaF2/α




















A1
0.01




0.01

0.08
3.1
1.00


A2
0.01




0.01

0.08
14.3
1.00


A3
0.01




0.01

0.08
8.5
1.00


A4
0.01




0.01

0.08
4.1
1.00


A5
0.01




0.01

0.08
3.1
0.95


A6
0.01




0.01

0.08
14.3
1.00


A7
0.01




0.01

0.08
6.5
1.00


A8
0.01




0.01

0.08
9.4
1.00


A9
0.01




0.01

0.08
4.8
1.00


A10
0.01




0.01

0.08
8.8
0.92


A11

0.01



0.01

0.08
4.7
1.00


A12


0.01


0.01

0.08
5.5
1.00


A13



0.01

0.01

0.08
9.4
0.94


A14
0.01



0.01
0.02

0.08
6.4
1.00


A15
0.01




0.01
4.80
0.08
4.7
1.00


A16
0.01




0.01

0.08
5.5
0.91


A17
0.01
0.01



0.02

0.08
6.4
1.00


A18

0.01



0.01

0.08
5.0
0.97


A19

0.01



0.01

0.08
5.5
1.00


A20

0.01
0.01


0.02

0.08
5.3
0.94


A21


0.01


0.01
2.50
0.08
5.4
1.00


A22


0.01


0.01
1.50
0.08
5.0
1.00


A23


0.01


0.01

0.08
5.2
0.94


A24



0.01

0.01

0.10
6.2
0.95


A25




0.01
0.01

0.10
11.3
0.91


A26




0.01
0.01

0.10
4.6
1.00


A27




0.01
0.01

0.10
6.8
1.00




















TABLE 2-3











CHEMICAL COMPOSITION OF FLUX






[mass % WITH RESPECT TO TOTAL MASS OF WIRE]






METAL FLUORIDE



















FILLING





TOTAL


WIRE


RATE





AMOUNT


No.
CATEGORY
REMARKS
(%)
CaF2
BaF2
SrF2
MgF2
LiF
[α]





A28
EXAMPLE

14.1
2.5



0.1
2.6


A29
EXAMPLE

16.3
4.8

0.1


4.9


A30
EXAMPLE
APPLIED
16.7
2.4
0.2



2.6




PTFE


A31
EXAMPLE

18.9
4.6


0.1
0.2
4.9


A32
EXAMPLE

13.8
3.0




3.0


A33
EXAMPLE

18.5
4.5




4.5


A34
EXAMPLE
APPLIED
14.0
2.9

0.1

0.1
3.1




PTFE


A35
EXAMPLE

18.6
4.6




4.6


A36
EXAMPLE

13.0
3.0




3.0


A37
EXAMPLE

13.3
3.2




3.2


A38
EXAMPLE

14.5
4.5




4.5


A39
EXAMPLE

16.0
5.8




5.8


A40
EXAMPLE

17.8
4.0




4.0


A41
EXAMPLE

17.9
4.0




4.0


A42
EXAMPLE

17.6
4.0




4.0


A43
EXAMPLE
APPLIED
18.6
4.0




4.0




PTFE


A44
EXAMPLE

18.2
4.0




4.0


A45
EXAMPLE

18.0
4.0




4.0


A46
EXAMPLE

19.0
5.0




5.0


A47
EXAMPLE

16.9
3.6




3.6


A48
EXAMPLE

16.0
4.2
0.2
0.1


4.5


A49
EXAMPLE
APPLIED
17.9
3.8




3.8




PTFE


A50
EXAMPLE

17.6
4.0


0.4

4.4


A51
EXAMPLE

16.8
3.1




3.1


A52
EXAMPLE

18.2
4.5




4.5


A53
EXAMPLE
APPLIED
20.2
5.8




5.8




PTFE


A54
EXAMPLE

16.5
3.0




3.0


A55
EXAMPLE

17.5
2.8




2.8














CHEMICAL COMPOSITION OF FLUX




[mass % WITH RESPECT TO TOTAL MASS OF WIRE]




METAL OXIDE























TOTAL



WIRE






AMOUNT



No.
TiO2
SiO2
MgO
Al2O3
ZrO2
CaO
[β]







A28
0.25
0.40



0.02
0.67



A29
0.12
0.24
0.05


0.02
0.43



A30
0.18
0.25
0.12
0.10

0.02
0.67



A31
0.10
0.22



0.12
0.44



A32
0.12
0.32



0.02
0.46



A33
0.15
0.35



0.02
0.52



A34
0.20
0.28

0.12

0.02
0.62



A35
0.15
0.33
0.15


0.02
0.65



A36
0.15
0.32

0.10

0.02
0.59



A37
0.20
0.35



0.02
0.57



A38
0.15
0.30
0.23


0.02
0.70



A39
0.20
0.35



0.02
0.57



A40
0.15
0.30



0.02
0.47



A41
0.15
0.30



0.02
0.47



A42
0.15
0.30



0.02
0.47



A43
0.15
0.30



0.02
0.47



A44
0.15
0.30



0.02
0.47



A45
0.15
0.30



0.19
0.64



A46
0.15
0.30



0.19
0.64



A47
0.11
0.22
0.12


0.02
0.47



A48
0.14
0.32



0.06
0.52



A49
0.34
0.34



0.02
0.70



A50
0.01
0.20


0.10
0.02
0.33



A51
0.01
0.20




0.21



A52
0.01
0.20

0.10

0.02
0.33



A53
0.01
0.20
0.10

0.10
0.02
0.43



A54
0.06
0.30



0.02
0.38



A55
0.05
0.20



0.02
0.27










[Table 2-4]










TABLE 2-4









CHEMICAL COMPOSITION OF FLUX




[mass % WITH RESPECT TO TOTAL MASS OF WIRE]










METAL CARBONATE


















WIRE





TOTAL
IRON
ARC




No.
CaCO3
BaCO3
SrCO3
MgCO3
Li2CO3
AMOUNT
POWDER
STABILIZER
α/β
CaF2/α


















A28


0.01
0.01

0.10
3.9
0.96


A29
0.01


0.01

0.10
11.4
0.98


A30
0.01


0.01

0.10
3.9
0.92


A31
0.01


0.01

0.10
11.1
0.94


A32
0.01


0.01

0.10
6.5
1.00


A33
0.01


0.01

0.10
8.7
1.00


A34
0.01


0.01

0.10
5.0
0.94


A35
0.01


0.01

0.10
7.1
1.00


A36
0.01


0.01

0.10
5.1
1.00


A37
0.01


0.01

0.10
5.6
1.00


A38
0.01


0.01

0.10
6.4
1.00


A39
0.01


0.01

0.10
10.2
1.00


A40
0.01


0.01

0.10
8.5
1.00


A41
0.01


0.01

0.10
8.5
1.00


A42
0.01


0.01

0.10
8.5
1.00


A43
0.01


0.01

0.10
8.5
1.00


A44
0.44
0.10
0.05
0.59
0.60
0.10
8.5
1.00


A45
0.01


0.01

0.10
6.3
1.00


A46
0.01


0.01

0.10
7.8
1.00


A47
0.01


0.01

0.08
7.7
1.00


A48
0.01


0.01

0.08
8.7
0.93


A49
0.01


0.01

0.08
5.4
1.00


A50
0.01


0.01

0.08
13.3
0.91


A51
0.01


0.01

0.08
14.8
1.00


A52
0.01


0.01

0.08
13.6
1.00


A53
0.01


0.01

0.08
13.5
1.00


A54
0.01


0.01

0.08
7.9
1.00


A55
0.01


0.01

0.08
10.4
1.00




















TABLE 2-5











CHEMICAL COMPOSITION OF FLUX






[mass % WITH RESPECT TO TOTAL MASS OF WIRE]






METAL FLUORIDE



















FILLING





TOTAL


WIRE


RATE





AMOUNT


No.
CATEGORY
REMARKS
(%)
CaF2
BaF2
SrF2
MgF2
LiF
[α]





B1
COMPARATIVE

11.8
1.8




1.8


B2
EXAMPLE
APPLIED
17.4
7.3




7.3




PTFE


B3


16.3
2.5




2.5


B4


16.6
3.5




3.5


B5


16.8
3.5




3.5


B6


18.5
3.8




3.8


B7


19.6
5.5




5.5


B8


16.6
2.4




2.4


B9


18.1
5.8




5.8


B10

APPLIED
16.8
3.8
0.5
0.3
0.1

4.7




PTFE


B11


16.8
2.8




2.8


B12


17.0
3.2




3.2


B13


15.7
3.2
0.1



3.3


B14

APPLIED
15.9
2.8


0.2

3.0




PTFE


B15


16.2
3.0

0.1


3.1


B16


15.8
3.0




3.0


B17


13.6
3.6

0.1


3.7


B18


13.8
3.6




3.6


B19


16.6
3.6


0.1
0.1
3.8


B20


15.7
3.2




3.2


B21


12.7
3.2


0.2

3.4


B22


13.0
3.4




3.4


B23

APPLIED
12.8
3.4
0.1
0.1


3.6




PTFE


B24


13.6
2.8




2.8


B25


15.8
2.8



0.1
2.9














CHEMICAL COMPOSITION OF FLUX




[mass % WITH RESPECT TO TOTAL MASS OF WIRE]




METAL OXIDE























TOTAL



WIRE






AMOUNT



No.
TiO2
SiO2
MgO
Al2O3
ZrO2
CaO
[β]







B1
0.15
0.20



0.02
0.37



B2
0.15
0.30



0.02
0.47



B3
0.45
0.20



0.02
0.67



B4
0.15
0.15



0.02
0.32



B5
0.15
0.56



0.02
0.73



B6
0.15
0.15



0.35
0.65



B7
0.40
0.50
0.10


0.02
1.02



B8
0.28
0.42
0.15


0.02
0.87



B9
0.12
0.24



0.02
0.38



B10
0.20
0.32



0.02
0.54



B11
0.20
0.28

0.10

0.02
0.60



B12
0.20
0.28



0.02
0.50



B13
0.15
0.24



0.10
0.49



B14
0.15
0.24
0.18
0.12

0.02
0.71



B15
0.25
0.25



0.02
0.52



B16
0.25
0.24



0.02
0.51



B17
0.10
0.33
0.20


0.02
0.65



B18
0.10
0.32
0.15


0.02
0.59



B19
0.20
0.36



0.05
0.61



B20
0.25
0.36



0.02
0.63



B21
0.15
0.32

0.15

0.02
0.64



B22
0.15
0.25

0.15

0.02
0.57



B23
0.24
0.23



0.02
0.49



B24
0.24
0.23



0.02
0.49



B25
0.16
0.36
0.12


0.02
0.66










[Table 2-6]










TABLE 2-6









CHEMICAL COMPOSITION OF FLUX




[mass % WITH RESPECT TO TOTAL MASS OF WIRE]










METAL CARBONATE


















WIRE





TOTAL
IRON
ARC




No.
CaCO3
BaCO3
SrCO3
MgCO3
Li2CO3
AMOUNT
POWDER
STABILIZER
α/β
CaF2/α





B1
0.01




0.01

0.08
4.9
1.00


B2
0.01




0.01

0.08
15.5 
1.00


B3
0.01




0.01

0.08
3.7
1.00


B4
0.01




0.01

0.08
10.9 
1.00


B5
0.01




0.01

0.08
4.8
1.00


B6
0.01




0.01

0.08
5.8
1.00


B7
0.01




0.01

0.08
5.4
1.00


B8
0.01




0.01

0.08
2.8
1.00


B9

0.01



0.01

0.08
15.3 
1.00


B10


0.01


0.01

0.08
8.7
0.81


B11



0.01

0.01

0.08
4.7
1.00


B12
0.01



0.01
0.02

0.08
6.4
1.00


B13
0.01




0.01

0.08
6.7
0.97


B14
0.01




0.01

0.08
4.2
0.93


B15
0.01
0.01



0.02

0.08
6.0
0.97


B16

0.01



0.01

0.08
5.9
1.00


B17

0.01



0.01

0.08
5.7
0.97


B18

0.01
0.01


0.02

0.08
6.1
1.00


B19


0.01


0.01

0.08
6.2
0.95


B20


0.01


0.01

0.08
5.1
1.00


B21


0.01


0.01
3.00
0.08
5.3
0.94


B22



0.01

0.01

0.08
6.0
1.00


B23




0.01
0.01

0.08
7.3
0.94


B24




0.01
0.01

0.08
5.7
1.00


B25




0.01
0.01

0.08
4.4
0.97




















TABLE 2-7











CHEMICAL COMPOSITION OF FLUX






[mass % WITH RESPECT TO TOTAL MASS OF WIRE]






METAL FLUORIDE



















FILLING





TOTAL


WIRE


RATE





AMOUNT


No.
CATEGORY
REMARKS
(%)
CaF2
BaF2
SrF2
MgF2
LiF
[α]





B26
COMPARATIVE

16.7
3.2


0.2

3.4


B27
EXAMPLE

14.2
3.2




3.2


B28


17.8
3.4

0.2


3.6


B29

APPLIED
17.2
3.4

0.1


3.5




PTFE


B30


17.7
3.2
0.1

0.1

3.4


B31

APPLIED
14.0
3.2



0.1
3.3




PTFE


B32


10.8
2.8
0.1
0.1


3.0


B33


17.5
3.3




3.3


B34


11.2
2.6

0.1


2.7


B35


20.2
5.7


0.1

5.8


B36


16.9
5.5




5.5


B37


16.3
4.8




4.8


B38


16.3
4.8




4.8


B39


19.8
4.8




4.8


B40


17.8
4.8




4.8


B41


14.7
1.8
0.1



1.9


B42


12.8
1.7
0.1



1.8


B43


18.0
7.0

0.5


7.5


B44


16.3
4.0
0.1

0.1

4.2


B45


20.6
3.0
0.1

0.1

3.2


B46


18.9
5.8




5.8


B47

APPLIED
19.6
4.5
0.3
0.1
0.1

5.0




PTFE


B48


17.3
2.8




2.8


B49


18.2
3.8




3.8


B50


16.6
2.4


0.1
0.1
2.6


B51


19.4
2.2


0.1
0.1
2.4














CHEMICAL COMPOSITION OF FLUX




[mass % WITH RESPECT TO TOTAL MASS OF WIRE]




METAL OXIDE























TOTAL



WIRE






AMOUNT



No.
TiO2
SiO2
MgO
Al2O3
ZrO2
CaO
[β]







B26
0.16
0.36

0.13

0.02
0.67



B27
0.15
0.32
0.10
0.12

0.02
0.71



B28
0.15
0.36



0.02
0.53



B29
0.22
0.25



0.05
0.52



B30
0.22
0.24



0.02
0.48



B31
0.25
0.26



0.02
0.53



B32
0.25
0.26



0.02
0.53



B33
0.15
0.32

0.10

0.02
0.59



B34
0.15
0.30
0.10


0.02
0.57



B35
0.20
0.26



0.02
0.48



B36
0.01
0.41



0.02
0.44



B37
0.01
0.34

0.05

0.02
0.42



B38
0.01
0.34

0.05

0.02
0.42



B39
0.01
0.34

0.05

0.65
1.05



B40
0.01
0.34

0.05

0.02
0.42



B41
0.15
0.20



0.02
0.37



B42
0.15
0.20



0.02
0.37



B43
0.30
0.20

0.05

0.02
0.57



B44
0.15
0.35

0.05

0.02
0.57



B45
0.12
0.23

0.05

0.02
0.42



B46
0.18
0.24


0.05
0.02
0.49



B47
0.20
0.32



0.02
0.54



B48
0.20
0.28

0.10

0.02
0.60



B49
0.20
0.28

0.10

0.02
0.60



B50
0.01
0.13

0.02

0.02
0.18



B51
0.01
0.20

0.01

0.01
0.23




















TABLE 2-8









CHEMICAL COMPOSITION OF FLUX




[mass % WITH RESPECT TO TOTAL MASS OF WIRE]










METAL CARBONATE


















WIRE





TOTAL
IRON
ARC




No.
CaCO3
BaCO3
SrCO3
MgCO3
Li2CO3
AMOUNT
POWDER
STABILIZER
α/β
CaF2/α


















B26


0.01
0.01

0.08
5.1
0.94


B27
0.01


0.01

0.08
4.5
1.00


B28
0.01


0.01

0.08
6.8
0.94


B29
0.01


0.01

0.08
6.7
0.97


B30
0.01


0.01

0.08
7.1
0.94


B31
0.01


0.01

0.08
6.2
0.97


B32
0.01


0.01

0.08
5.7
0.93


B33
0.01


0.01

0.08
5.6
1.00


B34
0.01


0.01

0.08
4.7
0.96


B35
0.01


0.01

0.08
12.1
0.98


B36
0.01


0.01

0.03
12.5
1.00


B37
0.01


0.01

0.09
11.4
1.00


B38
0.01


0.01

0.09
11.4
1.00


B39
0.01


0.01

0.09
4.6
1.00


B40
0.50
0.10
0.05
0.65
0.65
0.09
11.4
1.00


B41
0.01


0.01

0.09
5.1
0.95


B42
0.01


0.01

0.09
4.9
0.94


B43
0.01


0.01

0.09
13.2
0.93


B44
0.01


0.01

0.60
7.4
0.95


B45
0.01


0.01

0.08
7.6
0.94


B46
0.01


0.01

0.08
11.8
1.00


B47
0.01


0.01

0.08
9.3
0.90


B48
0.01


0.01

0.08
4.7
1.00


B49
1.01


1.01

1.08
6.3
1.00


B50
0.02


0.02
1.00
0.08
14.4
0.92


B51
0.02


0.02
5.50
0.08
10.4
0.92




















TABLE 2-9











CHEMICAL COMPOSITION OF FLUX






[mass % WITH RESPECT TO TOTAL MASS OF WIRE]






METAL FLUORIDE



















FILLING





TOTAL


WIRE


RATE





AMOUNT


No.
CATEGORY
REMARKS
(%)
CaF2
BaF2
SrF2
MgF2
LiF
[α]





A56
EXAMPLE

8.0
2.0




2.0


A57
EXAMPLE

14.0
7.0




7.0


A58
EXAMPLE

8.0
4.5




4.5


A59
EXAMPLE

8.0
2.7




2.7


A60
EXAMPLE

8.0
4.0




4.0


A61
EXAMPLE

8.0
3.5

0.2

0.1
3.8


A62
EXAMPLE

6.0
4.4
0.1



4.5


A63
EXAMPLE

8.0
3.2




3.2


A64
EXAMPLE
APPLIED
8.0
2.8




2.8




PTFE


A65
EXAMPLE

8.0
2.8




2.8


A66
EXAMPLE

8.0
3.4




3.4


A67
EXAMPLE

8.0
3.4


0.1
0.1
3.6


A68
EXAMPLE

8.0
3.7


0.2

3.9


A69
EXAMPLE

8.0
4.0




4.0


A70
EXAMPLE

5.5
4.3




4.3


A71
EXAMPLE

10.0
3.8




3.8


A72
EXAMPLE

11.0
3.8

0.1

0.1
4.0


A73
EXAMPLE

12.0
3.8




3.8


A74
EXAMPLE
APPLIED
9.0
4.8
0.1
0.1


5.0




PTFE


A75
EXAMPLE

8.0
5.6
0.2



5.8


A76
EXAMPLE

10.0
6.0




6.0


A77
EXAMPLE

12.0
6.3




6.3


A78
EXAMPLE

12.0
4.6




4.6


A79
EXAMPLE

11.0
4.9




4.9


A80
EXAMPLE

8.0
4.7
0.2
0.1
0.1
0.1
5.2














CHEMICAL COMPOSITION OF FLUX




[mass % WITH RESPECT TO TOTAL MASS OF WIRE]




METAL OXIDE























TOTAL



WIRE






AMOUNT



No.
TiO2
SiO2
MgO
Al2O3
ZrO2
CaO
[β]







A56
0.15
0.32



0.02
0.49



A57
0.15
0.32



0.02
0.49



A58
0.10
0.20



0.02
0.32



A59
0.40
0.47



0.03
0.90



A60
0.20
0.35



0.03
0.58



A61
0.20
0.35



0.03
0.58



A62
0.10
0.28



0.02
0.40



A63
0.10
0.30



0.02
0.42



A64
0.12
0.28



0.03
0.43



A65
0.30
0.25
0.15


0.03
0.73



A66
0.15
0.30
0.10
0.10

0.03
0.68



A67
0.24
0.32

0.15

0.03
0.74



A68
0.24
0.25



0.10
0.59



A69
0.15
0.36



0.03
0.54



A70
0.35
0.35
0.15


0.03
0.88



A71
0.24
0.28



0.02
0.54



A72
0.34
0.20



0.02
0.56



A73
0.10
0.23

0.24

0.05
0.62



A74
0.18
0.24
0.22


0.02
0.66



A75
0.12
0.23
0.10
0.12

0.02
0.59



A76
0.13
0.22
0.15


0.03
0.53



A77
0.15
0.33

0.05

0.03
0.56



A78
0.24
0.35
0.11


0.03
0.73



A79
0.18
0.34



0.02
0.54



A80
0.20
0.22
0.12
0.10

0.05
0.69










[Table 2-10]










TABLE 2-10









CHEMICAL COMPOSITION OF FLUX




[mass % WITH RESPECT TO TOTAL MASS OF WIRE]










METAL CARBONATE


















WIRE





TOTAL
IRON
ARC




No.
CaCO3
BaCO3
SrCO3
MgCO3
Li2CO3
AMOUNT
POWDER
STABILIZER
α/β
CaF2/α



















A56
0.01



0.01
3.8
0.09
4.1
1.00


A57
0.01



0.01
4.8
0.09
14.3
1.00


A58
0.01



0.01
2.6
0.09
14.1
1.00


A59
0.01



0.01
2.8
0.09
3.0
1.00


A60
0.01



0.01
2.8
0.09
6.9
1.00


A61
0.01



0.01
2.6
0.09
6.6
0.92


A62
0.01



0.01
1.9
0.09
11.3
0.98


A63
0.01



0.01
3.6
0.08
7.6
1.00


A64
0.01



0.01
4.2
0.08
6.5
1.00


A65
0.01



0.01
3.6
0.08
3.8
1.00


A66
0.01



0.01
3.2
0.08
5.0
1.00


A67
0.01



0.01
2.5
0.08
4.9
0.94


A68
0.01



0.01
2.7
0.08
6.6
0.95


A69
0.01



0.01
2.7
0.08
7.4
1.00


A70
0.01



0.01
1.2
0.08
4.9
1.00


A71
0.01



0.01

0.08
7.0
1.00


A72

0.01


0.01
2.4
0.08
7.1
0.95


A73

0.01


0.01
2.7
0.08
6.1
1.00


A74

0.01


0.01
1.2
0.08
7.6
0.96


A75

0.01


0.01

0.08
9.8
0.97


A76

0.01


0.01

0.08
11.3
1.00


A77

0.01


0.01

0.08
11.3
1.00


A78

0.01


0.01
1.6
0.08
6.3
1.00


A79


0.01

0.01
1.2
0.08
9.1
1.00


A80



0.01
0.01

0.08
7.5
0.90




















TABLE 2-11











CHEMICAL COMPOSITION OF FLUX






[mass % WITH RESPECT TO TOTAL MASS OF WIRE]






METAL FLUORIDE



















FILLING





TOTAL


WIRE


RATE





AMOUNT


No.
CATEGORY
REMARKS
(%)
CaF2
BaF2
SrF2
MgF2
LiF
[α]





A81
EXAMPLE
APPLIED
12.0
5.2




5.2




PTFE


A82


8.0
6.0




6.0


A83


8.0
6.2




6.2


A84


8.0
4.6


0.2

4.8


A85


8.0
5.3




5.3


A86


8.0
4.8



0.1
4.9


A87


6.5
4.6

0.2


4.8


A88


10.0
5.0




5.0


A89

APPLIED
10.0
4.8
0.1



4.9




PTFE


A90


8.0
5.0




5.0


A91


8.0
3.0




3.0


A92


8.0
5.8




5.8


A93


8.0
3.1



0.1
3.2


A94


8.0
5.7




5.7


A95


12.0
4.2




4.2


A96


10.0
4.2




4.2


A97


12.0
3.8




3.8


A98


8.0
4.5




4.5


A99


10.0
4.8




4.8


A100


14.0
4.2




4.2


A101


8.0
3.5




3.5


A102


8.0
3.2


0.3

3.5


A103


8.0
3.0


0.1
0.1
3.2


A104


8.0
2.9


0.2

3.1


A105

HAVING
16.5
3.1




3.1




GAP




(CAULKED)


A106

HAVING
12.6
4.5




4.5




GAP




(CAULKED)


A107


12.0
3.0




3.0


A108


8.0
6.0




6.0














CHEMICAL COMPOSITION OF FLUX




[mass % WITH RESPECT TO TOTAL MASS OF WIRE]




METAL OXIDE























TOTAL



WIRE






AMOUNT



No.
TiO2
SiO2
MgO
Al2O3
ZrO2
CaO
[β]







A81
0.22
0.34



0.02
0.58



A82
0.35
0.22



0.02
0.59



A83
0.14
0.28
0.10


0.03
0.55



A84
0.15
0.25



0.03
0.43



A85
0.18
0.28



0.03
0.49



A86
0.23
0.28
0.15


0.02
0.68



A87
0.16
0.26



0.19
0.61



A88
0.24
0.25

0.16

0.02
0.67



A89
0.16
0.22
0.10


0.02
0.50



A90
0.24
0.32

0.10

0.02
0.68



A91
0.15
0.24

0.13

0.03
0.55



A92
0.16
0.26

0.11

0.03
0.56



A93
0.30
0.36
0.10


0.03
0.79



A94
0.33
0.34
0.12


0.02
0.81



A95
0.22
0.31

0.10

0.02
0.65



A96
0.15
0.30



0.02
0.47



A97
0.20
0.35



0.03
0.58



A98
0.15
0.25



0.03
0.43



A99
0.15
0.30



0.03
0.48



A100
0.20
0.30

0.10

0.19
0.79



A101
0.01
0.20


0.10
0.03
0.24



A102
0.01
0.20
0.08


0.02
0.31



A103
0.01
0.20


0.10
0.02
0.23



A104
0.01
0.20



0.02
0.23



A105
0.01
0.20



0.02
0.23



A106
0.11
0.20



0.02
0.33



A107
0.06
0.20



0.03
0.29



A108
0.05
0.20
0.05
0.10

0.02
0.42










[Table 2-12]










TABLE 2-12









CHEMICAL COMPOSITION OF FLUX




[mass % WITH RESPECT TO TOTAL MASS OF WIRE]










METAL CARBONATE


















WIRE





TOTAL
IRON
ARC




No.
CaCO3
BaCO3
SrCO3
MgCO3
Li2CO3
AMOUNT
POWDER
STABILIZER
α/β
CaF2/α




















A81




0.01
0.01
4.5
0.08
9.0
1.00


A82
0.01




0.01

0.08
10.2
1.00


A83

0.01



0.01

0.08
11.3
1.00


A84

0.01



0.01
1.4
0.08
11.2
0.96


A85


0.01


0.01
1.1
0.08
10.8
1.00


A86


0.01


0.01
1.7
0.08
7.2
0.98


A87



0.01

0.01
1.2
0.08
7.9
0.96


A88




0.01
0.01
3.6
0.08
7.5
1.00


A89
0.01




0.01
3.3
0.08
9.8
0.98


A90

0.01



0.01
1.6
0.08
7.4
1.00


A91

0.01



0.01
3.9
0.08
5.5
1.00


A92


0.01


0.01
0.6
0.08
10.4
1.00


A93


0.01


0.01
2.6
0.08
4.1
0.97


A94



0.01

0.01
0.6
0.08
7.0
1.00


A95




0.01
0.01
2.2
0.08
6.5
1.00


A96
0.01




0.01
2.2
0.08
8.9
1.00


A97

0.01



0.01
2.6
0.08
6.6
1.00


A98

0.01



0.01
2.5
0.08
10.5
1.00


A99
0.50
0.02
0.02
0.02
0.02
0.58
1.6
0.08
10.0
1.00


A100
0.01




0.01
3.1
0.08
5.3
1.00


A101
0.01




0.01
2.6
0.08
14.6
1.00


A102
0.01


0.10

0.11
2.1
0.08
11.3
0.91


A103
0.01




0.01
2.4
0.08
13.9
0.94


A104
0.01



0.10
0.11
2.2
0.08
13.5
0.94


A105
0.01




0.01

0.08
13.5
1.00


A106
0.01




0.01

0.08
13.6
1.00


A107
0.01




0.01
3.9
0.09
10.3
1.00


A108
0.01




0.01
0.7
0.08
14.3
1.00




















TABLE 2-13











CHEMICAL COMPOSITION OF FLUX






[mass % WITH RESPECT TO TOTAL MASS OF WIRE]






METAL FLUORIDE



















FILLING





TOTAL


WIRE


RATE





AMOUNT


No.
CATEGORY
REMARKS
(%)
CaF2
BaF2
SrF2
MgF2
LiF
[α]





B52
COMPARATIVE

8.0
1.8




1.8


B53
EXAMPLE

8.0
7.1




7.1


B54


15.0
7.5


1.5

9.0


B55


10.0
2.7




2.7


B56


12.0
3.7




3.7


B57


10.0
3.7




3.7


B58

APPLIED
9.0
4.0




4.0




PTFE


B59


10.0
5.7




5.7


B60


8.0
2.5




2.5


B61


10.0
6.2


0.5

6.7


B62


8.0
4.6
0.4
0.4
0.2

5.6


B63


5.5
3.9
0.2



4.1


B64

APPLIED
8.0
4.5




4.5




PTFE


B65


8.0
4.2




4.2


B66


8.0
3.7

0.1
0.1
0.1
4.0


B67


8.0
4.0




4.0


B68


8.0
3.5

0.2


3.7


B69


8.0
4.9




4.9


B70


8.0
3.8



0.2
4.0


B71


8.0
4.6




4.6


B72


8.0
4.2
0.1
0.1


4.4


B73

APPLIED
5.5
4.5




4.5




PTFE


B74


8.0
3.9




3.9


B75


8.0
3.8

0.1


3.9














CHEMICAL COMPOSITION OF FLUX




[mass % WITH RESPECT TO TOTAL MASS OF WIRE]




METAL OXIDE























TOTAL



WIRE






AMOUNT



No.
TiO2
SiO2
MgO
Al2O3
ZrO2
CaO
[β]







B52
0.12
0.22



0.02
0.36



B53
0.10
0.40



0.03
0.53



B54
0.05
0.30



0.02
0.37



B55
0.48
0.20



0.05
0.73



B56
0.18
0.16



0.02
0.36



B57
0.14
0.55



0.03
0.72



B58
0.18
0.18



0.38
0.74



B59
0.40
0.50

0.10

0.05
1.05



B60
0.34
0.40
0.15


0.03
0.92



B61
0.18
0.22



0.03
0.43



B62
0.18
0.34



0.03
0.55



B63
0.20
0.32



0.08
0.60



B64
0.24
0.27
0.16


0.02
0.69



B65
0.29
0.23



0.02
0.54



B66
0.15
0.37
0.20


0.03
0.75



B67
0.14
0.36



0.10
0.60



B68
0.23
0.34
0.16
0.10

0.03
0.86



B69
0.36
0.24



0.05
0.65



B70
0.39
0.22



0.04
0.65



B71
0.28
0.34

0.18

0.04
0.84



B72
0.16
0.24
0.24
0.10

0.02
0.76



B73
0.20
0.30



0.02
0.52



B74
0.14
0.34



0.03
0.51



B75
0.15
0.28
0.15


0.03
0.61




















TABLE 2-14









CHEMICAL COMPOSITION OF FLUX




[mass % WITH RESPECT TO TOTAL MASS OF WIRE]










METAL CARBONATE


















WIRE





TOTAL
IRON
ARC




No.
CaCO3
BaCO3
SrCO3
MgCO3
Li2CO3
AMOUNT
POWDER
STABILIZER
α/β
CaF2/α



















B52
0.01



0.01
5.3
0.09
5.0
1.00


B53
0.01



0.01

0.09
13.4 
1.00


B54
0.01



0.01
3.3
0.09
24.3 
0.83


B55
0.01



0.01
3.9
0.09
3.7
1.00


B56
0.01



0.01
3.1
0.09
10.3 
1.00


B57
0.01



0.01
3.0
0.09
5.1
1.00


B58
0.01



0.01
2.4
0.09
5.4
1.00


B59
0.01



0.01

0.09
5.4
1.00


B60
0.01



0.01
3.9
0.09
2.7
1.00


B61
0.01



0.01
0.5
0.09
15.6 
0.93


B62
0.01



0.01
1.2
0.09
10.2 
0.82


B63
0.01



0.01
2.3
0.09
6.8
0.95


B64
0.01



0.01
2.0
0.09
6.5
1.00


B65
0.01



0.01
2.7
0.09
7.8
1.00


B66
0.01



0.01
2.5
0.09
5.3
0.93


B67

0.01


0.01
2.7
0.09
6.7
1.00


B68

0.01


0.01
2.1
0.09
4.3
0.95


B69

0.01


0.01
1.5
0.09
7.5
1.00


B70

0.01


0.01
2.4
0.09
6.2
0.95


B71

0.01


0.01
2.1
0.09
5.5
1.00


B72

0.01


0.01
2.4
0.09
5.8
0.95


B73

0.01


0.01
2.1
0.09
8.7
1.00


B74


0.01

0.01
2.2
0.09
7.6
1.00


B75



0.01
0.01
2.3
0.09
6.4
0.97




















TABLE 2-15











CHEMICAL COMPOSITION OF FLUX






[mass % WITH RESPECT TO TOTAL MASS OF WIRE]






METAL FLUORIDE



















FILLING





TOTAL


WIRE


RATE





AMOUNT


No.
CATEGORY
REMARKS
(%)
CaF2
BaF2
SrF2
MgF2
LiF
[α]





B76
COMPARATIVE

8.0
4.4




4.4


B77
EXAMPLE

8.0
3.6


0.1
0.1
3.8


B78


12.0
3.5
3.1



6.6


B79


8.0
4.0




4.0


B80


8.0
3.8


0.2

4.0


B81


8.0
4.2




4.2


B82


8.0
4.8




4.8


B83


8.0
4.0
0.1
0.1


4.2


B84


8.0
4.1

0.1

0.1
4.3


B85

APPLIED
6.0
4.1
0.1

0.1

4.3




PTFE


B86


10.0
2.6

0.1


2.7


B87


8.0
3.0




3.0


B88


11.0
5.8




5.8


B89


8.0
5.8




5.8


B90


8.0
5.0




5.0


B91


8.0
5.5




5.5


B92


8.0
1.8
0.1



1.9


B93


8.0
1.7
0.1



1.8


B94


14.0
7.0

0.5


7.5


B95


10.0
7.0
0.1

0.1

7.2


B96


10.0
4.8
0.1

0.1

5.0


B97


13.0
5.0
0.1


0.3
5.4


B98


10.0
3.5

0.2


3.7


B99


10.0
4.9




4.9


B100


10.0
3.8



0.2
4.0


B101


9.0
2.3



0.2
2.5














CHEMICAL COMPOSITION OF FLUX




[mass % WITH RESPECT TO TOTAL MASS OF WIRE]




METAL OXIDE























TOTAL



WIRE






AMOUNT



No.
TiO2
SiO2
MgO
Al2O3
ZrO2
CaO
[β]







B76
0.18
0.30

0.12

0.03
0.63



B77
0.24
0.28



0.02
0.54



B78
0.18
0.25
0.18
0.10

0.03
0.74



B79
0.25
0.36



0.02
0.63



B80
0.15
0.40



0.10
0.65



B81
0.23
0.32

0.08

0.02
0.65



B82
0.18
0.29
0.24


0.02
0.73



B83
0.22
0.31



0.03
0.56



B84
0.16
0.32

0.08

0.10
0.66



B85
0.16
0.34



0.03
0.53



B86
0.18
0.32
0.22


0.03
0.75



B87
0.18
0.28
0.12


0.03
0.61



B88
0.18
0.28

0.15

0.02
0.63



B89
0.18
0.28

0.15

0.02
0.63



B90
0.10
0.20



0.62
0.92



B91
0.18
0.28

0.15

0.03
0.64



B92
0.18
0.25



0.03
0.46



B93
0.18
0.25



0.02
0.45



B94
0.18
0.20

0.12

0.02
0.52



B95
0.18
0.20

0.15

0.03
0.56



B96
0.18
0.20

0.15

0.03
0.56



B97
0.15
0.20



0.10
0.45



B98
0.15
0.20



0.10
0.45



B99
0.15
0.20



0.10
0.45



B100
0.15
0.20



0.10
0.45



B101
0.01
0.11



0.05
0.17










[Table 2-16]










TABLE 2-16









CHEMICAL COMPOSITION OF FLUX




[mass % WITH RESPECT TO TOTAL MASS OF WIRE]










METAL CARBONATE


















WIRE





TOTAL
IRON
ARC




No.
CaCO3
BaCO3
SrCO3
MgCO3
Li2CO3
AMOUNT
POWDER
STABILIZER
α/β
CaF2/α




















B76




0.01
0.01
1.7
0.09
7.0
1.00


B77
0.01




0.01
2.4
0.09
7.0
0.95


B78

0.01



0.01
2.7
0.09
8.9
0.53


B79

0.01



0.01
2.2
0.09
6.3
1.00


B80


0.01


0.01
2.4
0.09
6.2
0.95


B81


0.01


0.01
1.8
0.09
6.5
1.00


B82



0.01

0.01
1.8
0.09
6.6
1.00


B83




0.01
0.01
1.7
0.09
7.5
0.95


B84
0.01




0.01
2.5
0.09
6.5
0.95


B85

0.01



0.01
1.5
0.09
8.1
0.95


B86





0.00
5.4
0.09
3.6
0.96


B87





0.00
3.2
0.09
4.9
1.00


B88





0.00
0.4
0.09
9.2
1.00


B89





0.00
1.0
0.09
9.2
1.00


B90





0.00
1.5
0.09
5.4
1.00


B91
0.65



0.01
0.66
1.2
0.09
8.6
1.00


B92





0.00
5.0
0.09
4.1
0.95


B93





0.00
5.2
0.09
4.0
0.94


B94




0.05
0.05
4.3
0.09
14.4
0.93


B95


0.01


0.01
1.5
0.09
12.9
0.97


B96
0.01




0.01
3.2
0.60
8.9
0.96


B97
0.01




0.01
0.3
0.10
12.0
0.93


B98
0.01


0.10

0.11
1.6
0.10
8.2
0.95


B99
0.01




0.01
3.8
0.09
10.9
1.00


B100
0.01



0.10
0.11
3.0
0.09
8.9
0.95


B101
0.01



0.10
0.11
3.0
0.09
14.7
0.92









[Table 3-1]









TABLE 3-1









CHEMICAL COMPOSITION OF ALLOY OF WIRE


WIRE

[mass % WITH RESPECT TO TOTAL MASS OF WIRE]















No.
CATEGORY
C
Si
Mn
P
S
Al
Ni


















A1
EXAMPLE
0.015
0.10
0.2
0.007
0.004
0.012
13.0


A2
EXAMPLE
0.015
0.10
0.2
0.007
0.004
0.012
14.0


A3
EXAMPLE
0.020
0.25
0.5
0.007
0.004
0.012
13.0


A4
EXAMPLE
0.020
0.25
0.5
0.007
0.004
0.012
14.0


A5
EXAMPLE
0.025
0.30
0.7
0.007
0.004
0.012
13.0


A6
EXAMPLE
0.025
0.30
0.7
0.007
0.004
0.012
13.0


A7
EXAMPLE
0.003
0.20
0.5
0.006
0.003
0.010
13.0


A8
EXAMPLE
0.040
0.20
0.5
0.006
0.003
0.010
13.0


A9
EXAMPLE
0.015
0.05
0.5
0.006
0.003
0.012
12.0


A10
EXAMPLE
0.015
0.40
0.5
0.006
0.003
0.012
12.0


A11
EXAMPLE
0.020
0.15
0.2
0.006
0.003
0.010
13.0


A12
EXAMPLE
0.020
0.15
0.8
0.006
0.003
0.010
12.0


A13
EXAMPLE
0.025
0.10
0.6
0.006
0.003
0.003
11.0


A14
EXAMPLE
0.025
0.10
0.6
0.006
0.003
0.050
11.0


A15
EXAMPLE
0.030
0.20
0.5
0.006
0.003
0.012
6.0


A16
EXAMPLE
0.030
0.20
0.5
0.006
0.003
0.012
16.0


A17
EXAMPLE
0.010
0.10
0.4
0.006
0.003
0.010
11.5


A18
EXAMPLE
0.010
0.10
0.4
0.006
0.003
0.010
11.5


A19
EXAMPLE
0.015
0.20
0.5
0.006
0.003
0.006
10.0


A20
EXAMPLE
0.015
0.20
0.5
0.006
0.003
0.006
10.0


A21
EXAMPLE
0.030
0.10
0.4
0.006
0.003
0.008
7.5


A22
EXAMPLE
0.030
0.10
0.4
0.006
0.003
0.008
7.5


A23
EXAMPLE
0.005
0.15
0.3
0.006
0.003
0.010
14.0


A24
EXAMPLE
0.010
0.30
0.3
0.006
0.003
0.010
14.0


A25
EXAMPLE
0.010
0.30
0.4
0.006
0.003
0.008
13.0


A26
EXAMPLE
0.010
0.15
0.3
0.006
0.003
0.015
7.5


A27
EXAMPLE
0.015
0.15
0.3
0.006
0.003
0.015
12.5









[Table 3-2]










TABLE 3-2








CHEMICAL COMPOSITION OF ALLOY OF WIRE




WIRE
[mass % WITH RESPECT TO TOTAL MASS OF WIRE]
SM
Ceq


















No.
Cu
Cr
Mo
V
Ti
Nb
B
Mg
REM
(%)
(%)




















A1








0.30
0.378


A2
0.2







0.30
0.403


A3
0.2







0.75
0.439


A4








0.75
0.464


A5








1.00
0.479


A6








1.00
0.479


A7
0.2






0.2
0.70
0.420


A8
0.2







0.70
0.457


A9
0.3



0.10



0.55
0.400


A10


0.2





0.90
0.465


A11

0.2


0.03



0.35
0.425


A12
0.2




0.02

0.2
0.95
0.460


A13
0.2





0.001

0.70
0.404


A14








0.70
0.404


A15
0.2







0.70
0.272


A16




0.02



0.70
0.522


A17
0.5







0.50
0.368


A18

0.5

0.10



0.4
0.50
0.475


A19
0.2

0.5





0.70
0.482


A20
0.1


0.20



0.2
0.70
0.371


A21




0.10



0.50
0.288


A22
0.1

0.3


0.10

0.4
0.50
0.363


A23
0.1
0.2


0.02

0.010

0.45
0.451


A24







0.6
0.60
0.423


A25
0.2
0.1
0.1
0.05
0.02
0.01
0.002
0.1
0.70
0.463


A26




0.02



0.45
0.254


A27

0.2
0.4





0.45
0.524









[Table 3-3]









TABLE 3-3









CHEMICAL COMPOSITION OF ALLOY OF WIRE


WIRE

[mass % WITH RESPECT TO TOTAL MASS OF WIRE]















No.
CATEGORY
C
Si
Mn
P
S
Al
Ni


















A28
EXAMPLE
0.020
0.10
0.8
0.006
0.003
0.030
10.5


A29
EXAMPLE
0.020
0.40
0.5
0.006
0.003
0.030
10.5


A30
EXAMPLE
0.015
0.25
0.4
0.006
0.003
0.012
13.0


A31
EXAMPLE
0.015
0.25
0.4
0.006
0.003
0.012
13.0


A32
EXAMPLE
0.020
0.15
0.5
0.006
0.003
0.008
10.0


A33
EXAMPLE
0.020
0.15
0.5
0.006
0.003
0.008
13.0


A34
EXAMPLE
0.020
0.20
0.5
0.006
0.003
0.008
10.0


A35
EXAMPLE
0.020
0.20
0.5
0.006
0.003
0.008
13.0


A36
EXAMPLE
0.010
0.10
0.6
0.006
0.003
0.008
9.0


A37
EXAMPLE
0.010
0.30
0.4
0.006
0.003
0.008
9.0


A38
EXAMPLE
0.030
0.10
0.6
0.006
0.003
0.008
9.0


A39
EXAMPLE
0.030
0.30
0.4
0.006
0.003
0.008
9.0


A40
EXAMPLE
0.020
0.20
0.5
0.006
0.003
0.008
13.0


A41
EXAMPLE
0.020
0.20
0.5
0.006
0.003
0.008
13.0


A42
EXAMPLE
0.020
0.20
0.5
0.006
0.003
0.008
13.0


A43
EXAMPLE
0.035
0.30
0.7
0.006
0.003
0.008
14.0


A44
EXAMPLE
0.020
0.20
0.5
0.006
0.003
0.008
13.0


A45
EXAMPLE
0.020
0.20
0.5
0.006
0.003
0.008
13.0


A46
EXAMPLE
0.020
0.20
0.5
0.006
0.003
0.008
13.0


A47
EXAMPLE
0.020
0.10
0.8
0.006
0.003
0.030
12.5


A48
EXAMPLE
0.020
0.40
0.5
0.006
0.003
0.030
10.5


A49
EXAMPLE
0.015
0.25
0.4
0.006
0.003
0.012
13.0


A50
EXAMPLE
0.030
0.08
0.4
0.006
0.004
0.011
12.8


A51
EXAMPLE
0.030
0.11
0.4
0.006
0.004
0.011
13.1


A52
EXAMPLE
0.030
0.08
0.4
0.006
0.004
0.011
13.3


A53
EXAMPLE
0.030
0.12
0.4
0.006
0.004
0.011
13.5


A54
EXAMPLE
0.015
0.25
0.3
0.008
0.004
0.010
13.0


A55
EXAMPLE
0.015
0.10
0.5
0.008
0.004
0.010
14.0









[Table 3-4]










TABLE 3-4








CHEMICAL COMPOSITION OF FLUX




WIRE
[mass % WITH RESPECT TO TOTAL MASS OF WIRE]
SM
Ceq


















No.
Cu
Cr
Mo
V
Ti
Nb
B
Mg
REM
(%)
(%)





















A28
0.2



0.01

0.002


0.90
0.420


A29
0.2



0.01
0.01

0.2

0.90
0.383


A30
0.2

0.1
0.05





0.65
0.446


A31
0.2
0.1
0.1

0.04




0.65
0.462


A32
0.2








0.65
0.360


A33
0.2






0.2

0.65
0.435


A34
0.2



0.01




0.70
0.362


A35
0.2



0.01




0.70
0.437


A36


0.3






0.70
0.414


A37
0.2
0.2


0.01




0.70
0.354


A38
0.2








0.70
0.359


A39


0.1
0.04



0.4

0.70
0.362


A40
0.2


0.03
0.01




0.70
0.439


A41
0.2


0.03
0.01



0.050
0.70
0.439


A42




0.01



0.010
0.70
0.437


A43








0.001
1.00
0.514


A44



0.05
0.01




0.70
0.440


A45
0.2



0.01




0.70
0.437


A46
0.2



0.01




0.70
0.437


A47
0.2



0.01

0.002


0.90
0.470


A48
0.2



0.01
0.01

0.2

0.90
0.383


A49
0.2

0.1
0.05





0.65
0.446


A50




0.02




0.48
0.420


A51




0.02


0.3

0.51
0.429


A52




0.02




0.48
0.433


A53




0.02


0.4

0.52
0.439


A54









0.55
0.400


A55
0.3








0.60
0.453









[Table 3-5]









TABLE 3-5









CHEMICAL COMPOSITION OF FLUX


WIRE

[mass % WITH RESPECT TO TOTAL MASS OF WIRE]















No.
CATEGORY
C
Si
Mn
P
S
Al
Ni





B1
COMPARATIVE
0.010
0.20
0.3
0.008
0.004
0.012
 9.5


B2
EXAMPLE
0.010
0.25
0.4
0.008
0.004
0.012
 9.5


B3

0.020
0.15
0.5
0.008
0.004
0.010
13.0


B4

0.020
0.15
0.4
0.008
0.004
0.012
12.5


B5

0.010
0.10
0.3
0.008
0.004
0.012
12.5


B6

0.015
0.15
0.5
0.008
0.004
0.010
14.0


B7

0.025
0.25
0.3
0.008
0.004
0.012
13.0


B8

0.025
0.20
0.4
0.008
0.004
0.012
13.0


B9

0.015
0.15
0.5
0.008
0.004
0.010
11.5


B10

0.015
0.15
0.5
0.008
0.004
0.010
11.5


B11

0.002
0.20
0.4
0.008
0.004
0.008
13.0


B12

0.045
0.20
0.4
0.008
0.004
0.008
13.0


B13

0.015
0.03
0.3
0.008
0.004
0.008
11.5


B14

0.015
0.48
0.3
0.008
0.004
0.008
11.5


B15

0.020
0.10
0.1
0.007
0.005
0.008
12.0


B16

0.020
0.10
0.9
0.007
0.005
0.008
12.0


B17

0.015
0.20
0.5
0.022
0.004
0.012
 9.0


B18

0.015
0.20
0.5
0.008
0.012
0.012
 9.0


B19

0.020
0.25
0.4
0.007
0.004
0.002
11.5


B20

0.020
0.25
0.4
0.008
0.004
0.056
11.5


B21

0.025
0.10
0.6
0.008
0.004
0.012
 5.5


B22

0.025
0.10
0.6
0.008
0.004
0.012
 8.0


B23

0.015
0.15
0.5
0.008
0.004
0.008
 8.0


B24

0.015
0.15
0.5
0.007
0.005
0.008
 9.0


B25

0.020
0.35
0.3
0.007
0.005
0.008
11.5









[Table 3-6]










TABLE 3-6








CHEMICAL COMPOSITION OF FLUX




WIRE
[mass % WITH RESPECT TO TOTAL MASS OF WIRE]
SM
Ceq


















No.
Cu
Cr
Mo
V
Ti
Nb
B
Mg
REM
(%)
(%)




















B1








0.50
0.306


B2








0.65
0.325


B3








0.65
0.435


B4
0.2







0.55
0.405


B5








0.40
0.377


B6








0.65
0.455


B7








0.55
0.410


B8
0.2







0.60
0.425


B9
0.3



0.02



0.65
0.392


B10








0.65
0.392


B11
0.2
0.1


0.02



0.60
0.422


B12
0.2







0.60
0.445


B13

0.1
0.2
0.05




0.33
0.427


B14
0.3



0.02

0.003
0.3
0.78
0.373


B15
0.3

0.2





0.20
0.391


B16







0.2
1.00
0.474


B17

0.1


0.05
0.02


0.70
0.352


B18
0.2
0.2

0.10


0.004

0.70
0.379


B19
0.2

0.2




0.2
0.65
0.435


B20
0.1

0.1
0.03
0.02



0.65
0.412


B21



0.04

0.01


0.70
0.270


B22
0.6
0.1




0.003
0.2
0.70
0.349


B23

0.6


0.02



0.65
0.425


B24
0.2

0.6

0.03


0.4
0.65
0.480


B25
0.2
0.1

0.30

0.02


0.65
0.414









[Table 3-7]









TABLE 3-7









CHEMICAL COMPOSITION OF FLUX


WIRE

[mass % WITH RESPECT TO TOTAL MASS OF WIRE]















No.
CATEGORY
C
Si
Mn
P
S
Al
Ni





B26
COMPARATIVE
0.020
0.35
0.3
0.007
0.005
0.008
12.0


B27
EXAMPLE
0.025
0.30
0.3
0.007
0.005
0.008
 9.5


B28

0.025
0.30
0.2
0.007
0.005
0.008
13.5


B29

0.015
0.20
0.2
0.007
0.004
0.012
12.0


B30

0.015
0.05
0.2
0.007
0.004
0.012
13.5


B31

0.010
0.30
0.8
0.007
0.004
0.012
10.0


B32

0.020
0.15
0.2
0.007
0.004
0.012
 7.0


B33

0.020
0.20
0.5
0.008
0.004
0.012
13.0


B34

0.015
0.05
0.6
0.008
0.004
0.010
 7.5


B35

0.015
0.20
0.4
0.008
0.004
0.010
13.5


B36

0.056
0.36
0.4
0.011
0.002
0.006
10.6


B37

0.041
0.12
0.6
0.002
0.008
0.384
10.6


B38

0.025
0.10
0.6
0.002
0.008
0.030
10.5


B39

0.035
0.20
0.6
0.002
0.008
0.025
13.5


B40

0.025
0.25
0.6
0.002
0.008
0.020
11.5


B41

0.040
0.20
0.6
0.002
0.008
0.027
12.0


B42

0.022
0.15
0.6
0.002
0.008
0.019
10.2


B43

0.035
0.25
0.6
0.002
0.008
0.022
 9.5


B44

0.030
0.20
0.6
0.002
0.008
0.034
10.5


B45

0.030
0.20
0.6
0.002
0.008
0.034
16.5


B46

0.010
0.10
0.3
0.008
0.004
0.012
12.5


B47

0.015
0.15
0.5
0.008
0.004
0.010
14.0


B48

0.015
0.10
0.5
0.008
0.004
0.010
13.5


B49

0.015
0.15
0.4
0.006
0.004
0.011
12.5


B50

0.015
0.15
0.4
0.006
0.004
0.011
12.5


B51

0.015
0.15
0.4
0.006
0.004
0.011
10.5









[Table 3-8]










TABLE 3-8








CHEMICAL COMPOSITION OF FLUX




WIRE
[mass % WITH RESPECT TO TOTAL MASS OF WIRE]
SM
Ceq


















No.
Cu
Cr
Mo
V
Ti
Nb
B
Mg
REM
(%)
(%)





B26
0.1



0.15


0.3

0.65
0.385


B27
0.3
0.1
0.2


0.15



0.60
0.395


B28



0.05


0.012


0.50
0.412


B29
0.2

0.2

0.02


0.7

0.40
0.407


B30
0.2








0.25
0.388


B31



0.08





1.10
0.412


B32
0.2




0.02



0.35
0.235


B33

0.2
0.3






0.70
0.552


B34
0.2

0.1

0.02

0.004


0.65
0.330


B35

0.1

0.03



0.2

0.60
0.450


B36
0.3



0.01




0.76
0.403


B37
0.4





0.002


0.72
0.411


B38
0.4







0.06
0.70
0.392


B39
0.4








0.80
0.481


B40
0.4








0.85
0.423


B41
0.4








0.80
0.448


B42
0.4








0.75
0.383


B43
0.4








0.85
0.383


B44
0.4








0.80
0.401


B45
0.4








0.80
0.551


B46









0.40
0.377


B47









0.65
0.455


B48
0.3








0.60
0.440


B49
0.2








0.55
0.400


B50
0.2








0.55
0.400


B51
0.2




0.04

0.4
0.02
0.55
0.350









[Table 3-9]










TABLE 3-9










CHEMICAL COMPOSITION OF FLUX


WIRE

HOOP
[mass % WITH RESPECT TO TOTAL MASS OF WIRE]
















No.
CATEGORY
No.
C
Si
Mn
P
S
Al
Ni



















A56
EXAMPLE
F4
0.010
0.15
0.4
0.006
0.004
0.011
14.5


A57
EXAMPLE
F4
0.010
0.15
0.4
0.006
0.004
0.011
13.3


A58
EXAMPLE
F4
0.020
0.15
0.3
0.006
0.004
0.011
13.3


A59
EXAMPLE
F4
0.020
0.15
0.3
0.006
0.004
0.011
14.5


A60
EXAMPLE
F4
0.030
0.10
0.2
0.006
0.004
0.011
13.3


A61
EXAMPLE
F4
0.030
0.40
0.6
0.006
0.004
0.011
13.3


A62
EXAMPLE
F6
0.003
0.20
0.5
0.006
0.004
0.011
7.8


A63
EXAMPLE
F3
0.040
0.20
0.4
0.006
0.004
0.011
11.5


A64
EXAMPLE
F3
0.015
0.05
0.4
0.006
0.004
0.011
11.5


A65
EXAMPLE
F3
0.015
0.40
0.3
0.006
0.004
0.011
11.5


A66
EXAMPLE
F3
0.015
0.20
0.2
0.006
0.004
0.011
11.5


A67
EXAMPLE
F3
0.015
0.15
0.8
0.006
0.004
0.011
11.5


A68
EXAMPLE
F5
0.030
0.18
0.5
0.006
0.004
0.011
11.5


A69
EXAMPLE
F5
0.030
0.18
0.5
0.006
0.004
0.003
11.5


A70
EXAMPLE
F1
0.030
0.15
0.5
0.006
0.004
0.011
6.0


A71
EXAMPLE
F4
0.030
0.15
0.5
0.006
0.004
0.011
16.0


A72
EXAMPLE
F4
0.025
0.15
0.4
0.006
0.004
0.011
13.3


A73
EXAMPLE
F4
0.015
0.15
0.3
0.006
0.004
0.011
13.3


A74
EXAMPLE
F3
0.015
0.20
0.3
0.006
0.004
0.011
11.5


A75
EXAMPLE
F4
0.025
0.20
0.4
0.006
0.004
0.011
13.8


A76
EXAMPLE
F4
0.025
0.25
0.3
0.006
0.004
0.011
13.9


A77
EXAMPLE
F4
0.025
0.25
0.3
0.006
0.004
0.011
13.6


A78
EXAMPLE
F4
0.025
0.30
0.3
0.006
0.004
0.011
13.3


A79
EXAMPLE
F4
0.025
0.30
0.3
0.006
0.004
0.011
13.3


A80
EXAMPLE
F2
0.010
0.20
0.5
0.006
0.004
0.011
9.0


A81
EXAMPLE
F2
0.010
0.20
0.2
0.006
0.004
0.011
8.3









[Table 3-10]










TABLE 3-10








CHEMICAL COMPOSITION OF FLUX




WIRE
[mass % WITH RESPECT TO TOTAL MASS OF WIRE]
SM
Ceq


















No.
Cu
Cr
Mo
V
Ti
Nb
B
Mg
REM
(%)
(%)




















A56








0.55
0.445


A57








0.55
0.415


A58
0.2







0.45
0.409


A59








0.45
0.439


A60
0.1
0.2

0.02




0.30
0.441


A61


0.1





1.00
0.504


A62
0.2
0.3


0.03



0.70
0.350


A63
0.2







0.60
0.403


A64



0.01


0.004
0.2
0.45
0.372


A65

0.1
0.1





0.70
0.414


A66
0.2

0.2


0.02


0.40
0.394


A67
0.1






0.2
0.95
0.442


A68





0.01

0.4
0.68
0.408


A69

0.2

0.06




0.68
0.453


A70
0.2

0.3
0.05
0.02



0.65
0.348


A71
0.2



0.02

0.004
0.2
0.65
0.520


A72
0.5







0.55
0.430


A73

0.5






0.45
0.504


A74
0.2

0.5

0.01



0.50
0.486


A75
0.1
0.2
0.1
0.20




0.60
0.524


A76
0.2

0.1

0.10



0.55
0.458


A77



0.04

0.10
0.003
0.2
0.55
0.428


A78
0.2





0.010
0.3
0.60
0.420


A79


0.2

0.03


0.6
0.60
0.470


A80
0.2
0.2
0.1
0.04
0.02
0.01
0.001
0.2
0.70
0.395


A81
0.2







0.40
0.259









[Table 3-11]










TABLE 3-11










CHEMICAL COMPOSITION OF FLUX


WIRE

HOOP
[mass % WITH RESPECT TO TOTAL MASS OF WIRE]
















No.
CATEGORY
No.
C
Si
Mn
P
S
Al
Ni



















A82
EXAMPLE
F4
0.020
0.20
0.5
0.006
0.004
0.011
13.3


A83
EXAMPLE
F3
0.025
0.20
0.5
0.006
0.004
0.011
11.8


A84
EXAMPLE
F3
0.030
0.30
0.6
0.006
0.004
0.011
11.5


A85
EXAMPLE
F2
0.015
0.30
0.4
0.006
0.004
0.011
8.3


A86
EXAMPLE
F4
0.015
0.15
0.4
0.006
0.004
0.011
13.3


A87
EXAMPLE
F2
0.015
0.20
0.5
0.006
0.004
0.011
8.3


A88
EXAMPLE
F4
0.015
0.15
0.4
0.006
0.004
0.011
13.1


A89
EXAMPLE
F2
0.015
0.20
0.5
0.006
0.004
0.011
8.1


A90
EXAMPLE
F4
0.015
0.15
0.4
0.006
0.004
0.011
13.3


A91
EXAMPLE
F2
0.010
0.15
0.3
0.006
0.004
0.011
8.3


A92
EXAMPLE
F2
0.010
0.30
0.4
0.006
0.004
0.011
8.3


A93
EXAMPLE
F2
0.030
0.15
0.3
0.006
0.004
0.011
9.0


A94
EXAMPLE
F2
0.030
0.30
0.4
0.006
0.004
0.011
8.3


A95
EXAMPLE
F4
0.025
0.20
0.5
0.006
0.004
0.011
13.3


A96
EXAMPLE
F4
0.020
0.10
0.4
0.006
0.004
0.011
13.3


A97
EXAMPLE
F4
0.035
0.25
0.6
0.006
0.004
0.011
13.3


A98
EXAMPLE
F4
0.025
0.15
0.4
0.006
0.004
0.011
13.3


A99
EXAMPLE
F4
0.015
0.15
0.4
0.006
0.004
0.011
13.3


A100
EXAMPLE
F3
0.030
0.05
0.4
0.006
0.004
0.011
12.5


A101
EXAMPLE
F3
0.030
0.08
0.4
0.006
0.004
0.011
12.8


A102
EXAMPLE
F3
0.030
0.11
0.4
0.006
0.004
0.011
13.1


A103
EXAMPLE
F3
0.030
0.08
0.4
0.006
0.004
0.011
13.3


A104
EXAMPLE
F3
0.030
0.12
0.4
0.006
0.004
0.011
13.5


A105
EXAMPLE
MILD
0.020
0.11
0.4
0.006
0.004
0.011
13.1




STEEL


A106
EXAMPLE
F1
0.020
0.08
0.4
0.006
0.004
0.011
13.3


A107
EXAMPLE
F4
0.010
0.20
0.5
0.006
0.004
0.011
13.3


A108
EXAMPLE
F4
0.015
0.05
0.4
0.006
0.004
0.045
13.4









[Table 3-12]










TABLE 3-12








CHEMICAL COMPOSITION OF FLUX




WIRE
[mass % WITH RESPECT TO TOTAL MASS OF WIRE]
SM
Ceq


















No.
Cu
Cr
Mo
V
Ti
Nb
B
Mg
REM
(%)
(%)





















A82
0.3
0.1
0.2
0.12





0.70
0.523


A83
0.2


0.10
0.02




0.70
0.419


A84

0.1
0.2




0.2

0.90
0.500


A85
0.2
0.1
0.1
0.05
0.02

0.002


0.70
0.350


A86
0.2








0.55
0.420


A87
0.2

0.2
0.05



0.3

0.70
0.368


A88
0.2



0.02




0.55
0.415


A89
0.2






0.4

0.70
0.309


A90
0.2



0.02

0.002


0.55
0.420


A91

0.1
0.1






0.45
0.319


A92
0.2
0.2



0.01



0.70
0.337


A93
0.2


0.05





0.45
0.315


A94


0.2






0.70
0.367


A95
0.2


0.06
0.02




0.70
0.453


A96




0.02



0.050
0.50
0.423


A97
0.2

0.1





0.010
0.85
0.503


A98
0.1



0.02



0.001
0.55
0.430


A99









0.55
0.420


A100




0.02


0.5

0.45
0.411


A101




0.02




0.48
0.420


A102




0.02


0.3
0.020
0.51
0.429


A103




0.02




0.48
0.433


A104




0.02


0.4

0.52
0.439


A105




0.02


0.3

0.51
0.419


A106




0.01


0.3

0.48
0.423


A107
0.2








0.70
0.434


A108
0.1



0.07


0.6
0.020
0.45
0.419









[Table 3-13]










TABLE 3-13










CHEMICAL COMPOSITION OF FLUX


WIRE

HOOP
[mass % WITH RESPECT TO TOTAL MASS OF WIRE]
















No.
CATEGORY
No.
C
Si
Mn
P
S
Al
Ni





B52
COMPARATIVE
F4
0.025
0.15
0.4
0.006
0.004
0.011
13.3


B53
EXAMPLE
F4
0.025
0.15
0.2
0.006
0.004
0.011
13.3


B54

F4
0.020
0.20
0.5
0.006
0.004
0.011
13.3


B55

F4
0.020
0.20
0.5
0.006
0.004
0.011
13.3


B56

F4
0.020
0.25
0.4
0.006
0.004
0.011
13.3


B57

F4
0.020
0.25
0.4
0.006
0.004
0.011
13.3


B58

F4
0.030
0.20
0.5
0.006
0.004
0.011
13.3


B59

F4
0.025
0.25
0.4
0.006
0.004
0.011
13.3


B60

F4
0.025
0.25
0.4
0.006
0.004
0.011
13.3


B61

F4
0.030
0.20
0.5
0.006
0.004
0.011
13.3


B62

F4
0.030
0.20
0.5
0.006
0.004
0.011
13.3


B63

F6
0.002
0.15
0.5
0.006
0.004
0.011
 7.8


B64

F3
0.044
0.15
0.5
0.006
0.004
0.011
11.5


B65

F3
0.025
0.03
0.3
0.006
0.004
0.011
11.5


B66

F3
0.025
0.46
0.3
0.006
0.004
0.011
11.5


B67

F3
0.020
0.30
0.1
0.006
0.004
0.011
11.5


B68

F3
0.020
0.10
0.9
0.006
0.004
0.011
11.5


B69

F3
0.030
0.20
0.6
0.022
0.004
0.011
11.5


B70

F3
0.030
0.20
0.6
0.006
0.012
0.011
11.5


B71

F5
0.020
0.20
0.3
0.006
0.004
0.002
11.5


B72

F5
0.020
0.20
0.3
0.006
0.004
0.056
11.5


B73

F1
0.015
0.20
0.4
0.006
0.004
0.011
 5.5


B74

F3
0.020
0.25
0.5
0.006
0.004
0.011
11.5


B75

F3
0.020
0.25
0.4
0.006
0.004
0.011
11.5


B76

F3
0.020
0.15
0.3
0.006
0.004
0.011
11.5


B77

F3
0.015
0.20
0.5
0.006
0.004
0.011
11.5









[Table 3-14]










TABLE 3-14








CHEMICAL COMPOSITION OF FLUX




WIRE
[mass % WITH RESPECT TO TOTAL MASS OF WIRE]
SM
Ceq


















No.
Cu
Cr
Mo
V
Ti
Nb
B
Mg
REM
(%)
(%)




















B52








0.55
0.430


B53




0.02



0.35
0.397


B54



0.04



0.4
0.70
0.447


B55








0.70
0.444


B56
0.2







0.65
0.430


B57




0.02



0.65
0.430


B58







0.2
0.70
0.454


B59
0.2


0.05



0.4
0.65
0.438


B60




0.03



0.65
0.435


B61
0.2







0.70
0.454


B62








0.70
0.454


B63
0.2
0.2


0.02



0.65
0.327


B64


0.2





0.65
0.471


B65
0.2



0.02



0.33
0.364


B66



0.05




0.76
0.385


B67
0.3


0.03




0.40
0.339


B68
0.2




0.02

0.2
1.00
0.462


B69

0.1
0.1

0.02



0.80
0.471


B70
0.2


0.04




0.80
0.429


B71


0.2


0.02
0.003

0.50
0.416


B72

0.1

0.04




0.50
0.389


B73


0.1

0.02


0.2
0.60
0.253


B74
0.6
0.1






0.75
0.421


B75

0.6


0.03



0.65
0.505


B76


0.6

0.02


0.2
0.45
0.514


B77
0.3


0.30


0.003

0.70
0.416









[Table 3-15]










TABLE 3-15










CHEMICAL COMPOSITION OF FLUX


WIRE

HOOP
[mass % WITH RESPECT TO TOTAL MASS OF WIRE]
















No.
CATEGORY
No.
C
Si
Mn
P
S
Al
Ni





B78
COMPARATIVE
F3
0.015
0.30
0.4
0.006
0.004
0.011
11.5


B79
EXAMPLE
F3
0.015
0.30
0.4
0.006
0.004
0.011
11.5


B80

F3
0.020
0.15
0.5
0.006
0.004
0.011
11.5


B81

F3
0.020
0.15
0.5
0.006
0.004
0.011
11.5


B82

F3
0.010
0.05
0.2
0.006
0.004
0.011
11.5


B83

F3
0.010
0.30
0.8
0.006
0.004
0.011
11.5


B84

F6
0.005
0.10
0.2
0.006
0.004
0.011
 7.8


B85

F2
0.030
0.20
0.7
0.006
0.004
0.011
 8.3


B86

F2
0.025
0.20
0.6
0.006
0.004
0.011
 8.1


B87

F2
0.015
0.15
0.8
0.006
0.004
0.011
 8.3


B88

F4
0.015
0.30
0.4
0.006
0.004
0.011
13.3


B89

F3
0.015
0.15
0.4
0.006
0.004
0.011
11.5


B90

F3
0.015
0.15
0.4
0.006
0.004
0.011
11.5


B91

F3
0.020
0.20
0.5
0.006
0.004
0.011
11.5


B92

F3
0.020
0.20
0.5
0.006
0.004
0.011
11.5


B93

F3
0.025
0.15
0.4
0.006
0.004
0.011
11.5


B94

F3
0.025
0.25
0.3
0.006
0.004
0.011
11.5


B95

F3
0.030
0.15
0.6
0.006
0.004
0.011
11.5


B96

F3
0.030
0.15
0.6
0.006
0.004
0.011
13.3


B97

F4
0.030
0.15
0.3
0.006
0.004
0.011
16.5


B98

F2
0.030
0.30
0.6
0.006
0.004
0.011
11.5


B99

F1
0.015
0.30
0.4
0.006
0.004
0.011
 8.3


B100

F3
0.015
0.15
0.4
0.006
0.004
0.011
13.3


B101

F3
0.015
0.15
0.4
0.006
0.004
0.011
12.5









[Table 3-16]










TABLE 3-16








CHEMICAL COMPOSITION OF FLUX




WIRE
[mass % WITH RESPECT TO TOTAL MASS OF WIRE]
SM
Ceq


















No.
Cu
Cr
Mo
V
Ti
Nb
B
Mg
REM
(%)
(%)





B78
0.2



0.15




0.70
0.382


B79





0.15

0.4

0.70
0.382


B80
0.1
0.1
0.1



0.012


0.65
0.442


B81



0.05



0.7

0.65
0.401


B82
0.2
0.2


0.03




0.25
0.373


B83


0.1




0.4

1.10
0.468


B84
0.2




0.02



0.30
0.238


B85

0.3
0.4
0.15





0.90
0.533


B86
0.2

0.2



0.002


0.80
0.386


B87
0.2


0.08
0.02




0.95
0.368


B88


0.2




0.3

0.70
0.477


B89

0.1

0.03



0.2
0.055
0.55
0.398


B90



0.03





0.55
0.378


B91

0.1

0.03



0.2

0.70
0.421


B92









0.70
0.399


B93
0.2

0.1




0.1

0.55
0.410


B94




0.02




0.55
0.373


B95
0.1








0.75
0.424


B96
0.1








0.75
0.469


B97
0.1








0.45
0.499


B98

0.1
0.2




0.2

0.90
0.500


B99
0.2
0.1
0.1
0.05
0.02

0.002


0.70
0.350


B100
0.2








0.55
0.420


B101
0.2








0.55
0.400


















TABLE 4-1









WELDING CONDITION




















WELDING
HEAT
PREHEATING
INTERPASS

FLOW


WIRE

CURRENT
VOLTAGE
RATE
INPUT
TEMPERATURE
TEMPERATURE
SHIELDING
RATE


No.
CATEGORY
[A]
[V]
[cm/min]
[kJ/cm]
[° C.]
[° C.]
GAS
[L/min]





A1
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A2
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A3
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A4
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A5
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A6
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A7
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A8
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A9
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A10
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A11
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A12
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A13
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A14
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A15
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A16
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A17
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A18
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A19
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A20
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A21
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A22
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A23
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A24
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A25
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A26
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25

















TABLE 4-2








WELDING CONDITION




















WELDING
HEAT
PREHEATING
INTERPASS

FLOW


WIRE

CURRENT
VOLTAGE
RATE
INPUT
TEMPERATURE
TEMPERATURE
SHIELDING
RATE


No.
CATEGORY
[A]
[V]
[cm/min]
[kJ/cm]
[° C.]
[° C.]
GAS
[L/min]





A27
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A28
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A29
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A30
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A31
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A32
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar—1.0% O2
25


A33
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar—1.0% O2
25


A34
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar—1.5% O2
25


A35
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar—1.5% O2
25


A36
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A37
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A38
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A39
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A40
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
He
25


A41
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A42
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A43
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A44
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A45
EXAMPLE
280
25
30
14.0
50
150 OR LESS
Ar
25


A46
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A47
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar—1.0% CO2
25


A48
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
He—1.0% O2
25


A49
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
He—1.0% CO2
25


A50
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A51
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A52
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A53
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A54
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A55
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25

















TABLE 4-3








WELDING CONDITION




















WELDING
HEAT
PREHEATING
INTERPASS

FLOW


WIRE

CURRENT
VOLTAGE
RATE
INPUT
TEMPERATURE
TEMPERATURE
SHIELDING
RATE


No.
CATEGORY
[A]
[V]
[cm/min]
[kJ/cm]
[° C.]
[° C.]
GAS
[L/min]





B1
COMPARATIVE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


B2
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


B3

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B4

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B5

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B6

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B7

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B8

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B9

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B10

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B11

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B12

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B13

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B14

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B15

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B16

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B17

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B18

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B19

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B20

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B21

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B22

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B23

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B24

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B25

280
25
30
14.0
NONE
150 OR LESS
Ar
25

















TABLE 4-4








WELDING CONDITION




















WELDING
HEAT
PREHEATING
INTERPASS

FLOW


WIRE

CURRENT
VOLTAGE
RATE
INPUT
TEMPERATURE
TEMPERATURE
SHIELDING
RATE


No.
CATEGORY
[A]
[V]
[cm/min]
[kJ/cm]
[° C.]
[° C.]
GAS
[L/min]





B26
COMPARATIVE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


B27
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


B28

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B29

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B30

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B31

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B32

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B33

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B34

280
25
30
14.0
NONE
150 OR LESS
Ar—2.0% O2
25


B35

280
25
30
14.0
NONE
150 OR LESS
Ar—2.0% O2
25


B36

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B37

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B38

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B39

280
25
30
14.0
50
150 OR LESS
Ar
25


B40

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B41

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B42

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B43

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B44

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B45

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B46

280
25
30
14.0
NONE
150 OR LESS
Ar—2.0% CO2
25


B47

280
25
30
14.0
NONE
150 OR LESS
He—2.0% O2
25


B48

280
25
30
14.0
NONE
150 OR LESS
He—2.0% CO2
25


B49

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B50

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B51

280
25
30
14.0
NONE
150 OR LESS
Ar
25

















TABLE 4-5








WELDING CONDITION




















WELDING
HEAT
PREHEATING
INTERPASS

FLOW


WIRE

CURRENT
VOLTAGE
RATE
INPUT
TEMPERATURE
TEMPERATURE
SHIELDING
RATE


No.
CATEGORY
[A]
[V]
[cm/min]
[kJ/cm]
[° C.]
[° C.]
GAS
[L/min]





A56
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A57
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A58
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A59
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A60
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A61
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A62
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A63
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A64
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A65
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A66
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A67
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A68
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A69
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A70
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A71
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A72
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A73
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A74
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A75
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A76
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A77
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A78
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A79
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A80
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A81
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A82
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A83
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A84
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A85
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar—1.0% O2
25


A86
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar—1.0% O2
25


A87
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar—1.0% O2
25


A88
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar—1.5% O2
25


A89
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar—1.5% O2
25


A90
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar—1.5% O2
25


A91
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar—1.0 CO2
25


A92
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A93
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
He
25


A94
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
He—1.0% O2
25


A95
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
He—1.0% CO2
25


A96
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A97
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A98
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A99
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A100
EXAMPLE
280
25
30
14.0
50
150 OR LESS
Ar
25


A101
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A102
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A103
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A104
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A105
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A106
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A107
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


A108
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar—2.0% O2
25

















TABLE 4-6








WELDING CONDITION




















WELDING
HEAT
PREHEATING
INTERPASS

FLOW


WIRE

CURRENT
VOLTAGE
RATE
INPUT
TEMPERATURE
TEMPERATURE
SHIELDING
RATE


No.
CATEGORY
[A]
[V]
[cm/min]
[kJ/cm]
[° C.]
[° C.]
GAS
[L/min]





B52
COMPARATIVE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


B53
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


B54

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B55

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B56

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B57

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B58

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B59

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B60

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B61

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B62

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B63

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B64

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B65

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B66

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B67

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B68

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B69

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B70

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B71

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B72

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B73

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B74

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B75

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B76

280
25
30
14.0
NONE
150 OR LESS
Ar
25

















TABLE 4-7








WELDING CONDITION




















WELDING
HEAT
PREHEATING
INTERPASS

FLOW


WIRE

CURRENT
VOLTAGE
RATE
INPUT
TEMPERATURE
TEMPERATURE
SHIELDING
RATE


No.
CATEGORY
[A]
[V]
[cm/min]
[kJ/cm]
[° C.]
[° C.]
GAS
[L/min]





B77
COMPARATIVE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


B78
EXAMPLE
280
25
30
14.0
NONE
150 OR LESS
Ar
25


B79

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B80

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B81

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B82

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B83

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B84

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B85

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B86

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B87

280
25
30
14.0
NONE
150 OR LESS
Ar—2.0% O2
25


B88

280
25
30
14.0
50
150 OR LESS
Ar—2.0% O2
25


B89

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B90

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B91

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B92

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B93

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B94

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B95

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B96

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B97

280
25
30
14.0
NONE
150 OR LESS
Ar
25


B98

280
25
30
14.0
NONE
150 OR LESS
Ar—2.0% CO2
25


B99

280
25
30
14.0
NONE
150 OR LESS
He—2.0% O2
25


B100

280
25
30
14.0
NONE
150 OR LESS
He—2.0% CO2
25


B101

280
25
30
14.0
NONE
150 OR LESS
Ar
25























TABLE 5-1











CHARPY
AMOUNT








ABSORBED
OF OXYGEN
Y-GROOVE
AMOUNT OF




YIELD
TENSILE
ENERGY
IN WELD
WELD
DIFFUSIBLE


WIRE

STRENGTH
STRENGTH
AT −196° C.
METAL
CRACKING
HYDROGEN


No.
CATEGORY
[MPa]
[MPa]
[J]
[ppm]
TEST
[ml/100 g]





A1
EXAMPLE
675
721
60
94
NO CRACKING
0.6


A2
EXAMPLE
669
709
61
104
NO CRACKING
0.4


A3
EXAMPLE
687
736
63
97
NO CRACKING
0.5


A4
EXAMPLE
672
725
60
102
NO CRACKING
0.5


A5
EXAMPLE
720
766
52
109
NO CRACKING
0.4


A6
EXAMPLE
719
778
50
89
NO CRACKING
0.6


A7
EXAMPLE
616
662
68
99
NO CRACKING
0.5


A8
EXAMPLE
769
828
54
90
NO CRACKING
0.6


A9
EXAMPLE
682
733
61
96
NO CRACKING
0.6


A10
EXAMPLE
700
745
57
105
NO CRACKING
0.4


A11
EXAMPLE
671
716
63
93
NO CRACKING
0.6


A12
EXAMPLE
706
752
53
93
NO CRACKING
0.5


A13
EXAMPLE
699
740
62
87
NO CRACKING
0.6


A14
EXAMPLE
685
736
59
99
NO CRACKING
0.4


A15
EXAMPLE
626
695
67
104
NO CRACKING
0.5


A16
EXAMPLE
728
793
56
90
NO CRACKING
0.5


A17
EXAMPLE
716
772
58
105
NO CRACKING
1.4


A18
EXAMPLE
720
786
56
93
NO CRACKING
0.6


A19
EXAMPLE
742
794
59
82
NO CRACKING
0.5


A20
EXAMPLE
724
779
60
94
NO CRACKING
0.3


A21
EXAMPLE
749
802
55
88
NO CRACKING
0.6


A22
EXAMPLE
726
782
57
97
NO CRACKING
0.6


A23
EXAMPLE
744
791
54
95
NO CRACKING
0.5


A24
EXAMPLE
703
743
61
100
NO CRACKING
0.5


A25
EXAMPLE
727
760
58
106
NO CRACKING
0.7




















COLD





WIRE
TENSILE

CRACKING
OVERALL




No.
STRENGTH
TOUGHNESS
RESISTANCE
DETERMINATION
REMARKS






A1
PASS
PASS
PASS
PASS




A2
PASS
PASS
PASS
PASS




A3
PASS
PASS
PASS
PASS




A4
PASS
PASS
PASS
PASS




A5
PASS
PASS
PASS
PASS




A6
PASS
PASS
PASS
PASS




A7
PASS
PASS
PASS
PASS




A8
PASS
PASS
PASS
PASS




A9
PASS
PASS
PASS
PASS




A10
PASS
PASS
PASS
PASS




A11
PASS
PASS
PASS
PASS




A12
PASS
PASS
PASS
PASS




A13
PASS
PASS
PASS
PASS




A14
PASS
PASS
PASS
PASS




A15
PASS
PASS
PASS
PASS




A16
PASS
PASS
PASS
PASS




A17
PASS
PASS
PASS
PASS




A18
PASS
PASS
PASS
PASS




A19
PASS
PASS
PASS
PASS




A20
PASS
PASS
PASS
PASS




A21
PASS
PASS
PASS
PASS




A22
PASS
PASS
PASS
PASS




A23
PASS
PASS
PASS
PASS




A24
PASS
PASS
PASS
PASS




A25
PASS
PASS
PASS
PASS























TABLE 5-2











CHARPY
AMOUNT








ABSORBED
OF OXYGEN
Y-GROOVE
AMOUNT OF




YIELD
TENSILE
ENERGY
IN WELD
WELD
DIFFUSIBLE


WIRE

STRENGTH
STRENGTH
AT −196° C.
METAL
CRACKING
HYDROGEN


No.
CATEGORY
[MPa]
[MPa]
[J]
[ppm]
TEST
[ml/100 g]





A26
EXAMPLE
619
666
68
94
NO CRACKING
0.6


A27
EXAMPLE
772
819
54
90
NO CRACKING
0.4


A28
EXAMPLE
672
719
52
99
NO CRACKING
0.5


A29
EXAMPLE
659
702
54
85
NO CRACKING
0.7


A30
EXAMPLE
710
744
62
94
NO CRACKING
0.6


A31
EXAMPLE
713
751
60
108
NO CRACKING
0.9


A32
EXAMPLE
645
698
63
118
NO CRACKING
0.6


A33
EXAMPLE
721
764
59
129
NO CRACKING
0.6


A34
EXAMPLE
697
741
54
153
NO CRACKING
0.4


A35
EXAMPLE
736
787
53
149
NO CRACKING
0.5


A36
EXAMPLE
673
725
65
94
NO CRACKING
0.5


A37
EXAMPLE
669
713
63
89
NO CRACKING
0.4


A38
EXAMPLE
732
783
55
99
NO CRACKING
0.6


A39
EXAMPLE
741
791
58
83
NO CRACKING
0.5


A40
EXAMPLE
722
769
62
95
NO CRACKING
0.6


A41
EXAMPLE
655
752
55
101
NO CRACKING
0.5


A42
EXAMPLE
670
800
58
110
NO CRACKING
0.6


A43
EXAMPLE
785
890
51
96
NO CRACKING
0.4


A44
EXAMPLE
698
768
60
93
NO CRACKING
0.6


A45
EXAMPLE
680
742
55
110
NO CRACKING
1.4


A46
EXAMPLE
703
756
65
94
NO CRACKING
0.5


A47
EXAMPLE
720
766
52
85
NO CRACKING
0.6


A48
EXAMPLE
719
778
50
81
NO CRACKING
0.4


A49
EXAMPLE
616
662
68
84
NO CRACKING
0.6


A50
EXAMPLE
670
742
84
78
NO CRACKING
0.8


A51
EXAMPLE
658
752
72
76
NO CRACKING
0.7


A52
EXAMPLE
663
774
95
72
NO CRACKING
0.8


A53
EXAMPLE
710
831
79
76
NO CRACKING
0.6


A54
EXAMPLE
705
730
63
103
NO CRACKING
0.6


A55
EXAMPLE
710
749
61
97
NO CRACKING
0.6




















COLD





WIRE
TENSILE

CRACKING
OVERALL




No.
STRENGTH
TOUGHNESS
RESISTANCE
DETERMINATION
REMARKS






A26
PASS
PASS
PASS
PASS




A27
PASS
PASS
PASS
PASS




A28
PASS
PASS
PASS
PASS




A29
PASS
PASS
PASS
PASS




A30
PASS
PASS
PASS
PASS




A31
PASS
PASS
PASS
PASS




A32
PASS
PASS
PASS
PASS




A33
PASS
PASS
PASS
PASS




A34
PASS
PASS
PASS
PASS




A35
PASS
PASS
PASS
PASS




A36
PASS
PASS
PASS
PASS




A37
PASS
PASS
PASS
PASS




A38
PASS
PASS
PASS
PASS




A39
PASS
PASS
PASS
PASS




A40
PASS
PASS
PASS
PASS




A41
PASS
PASS
PASS
PASS




A42
PASS
PASS
PASS
PASS




A43
PASS
PASS
PASS
PASS




A44
PASS
PASS
PASS
PASS




A45
PASS
PASS
PASS
PASS
NO CRACKING WITH








PREHEATING








TEMPERATURE OF








50° C.



A46
PASS
PASS
PASS
PASS




A47
PASS
PASS
PASS
PASS




A48
PASS
PASS
PASS
PASS




A49
PASS
PASS
PASS
PASS




A50
PASS
PASS
PASS
PASS




A51
PASS
PASS
PASS
PASS




A52
PASS
PASS
PASS
PASS




A53
PASS
PASS
PASS
PASS




A54
PASS
PASS
PASS
PASS




A55
PASS
PASS
PASS
PASS























TABLE 5-3











CHARPY
AMOUNT








ABSORBED
OF OXYGEN
Y-GROOVE
AMOUNT OF




YIELD
TENSILE
ENERGY
IN WELD
WELD
DIFFUSIBLE


WIRE

STRENGTH
STRENGTH
AT −196° C.
METAL
CRACKING
HYDROGEN


No.
CATEGORY
[MPa]
[MPa]
[J]
[ppm]
TEST
[ml/100 g]












B1
COMPARATIVE
NOT EVALUATED DUE TO UNSTABLE ARC


B2
EXAMPLE
NOT EVALUATED DUE TO A LOT OF FUME AND BAD WELDING EFFICIENCY














B3

710
753
42
176
—
—









B4

NOT EVALUATED DUE TO BAD SLAG PEELABILITY














B5

653
706
39
193
—
—


B6

708
749
59
110
CRACKING
1.9


B7

689
735
36
206
—
—


B8

705
756
46
169
—
—









B9

NOT EVALUATED DUE TO UNSTABLE ARC


B10

NOT EVALUATED DUE TO UNSTABLE ARC














B11

599
642
68
120
—
—


B12

811
864
45
99
—
—









B13

NOT EVALUATED DUE TO OCCURRENCE OF WELD DEFECT














B14

718
762
32
103
—
—


B15

720
769
42
148
—
—


B16

727
778
46
92
—
—


B17

708
752
37
100
—
—


B18

712
755
40
98
—
—


B19

719
780
43
176
—
—


B20

715
761
46
105
—
—


B21

724
771
38
102
—
—


B22

698
744
42
98
—
—


B23

726
787
46
109
—
—


B24

781
821
43
95
—
—


B25

725
770
45
93
—
—




















COLD





WIRE
TENSILE

CRACKING
OVERALL




No.
STRENGTH
TOUGHNESS
RESISTANCE
DETERMINATION
REMARKS






B1
—
—
—
FAIL




B2
—
—
—
FAIL




B3
PASS
FAIL
—
FAIL




B4
—
—
—
FAIL




B5
PASS
FAIL
—
FAIL




B6
PASS
PASS
FAIL
FAIL




B7
PASS
FAIL
—
FAIL




B8
PASS
FAIL
—
FAIL




B9
—
—
—
FAIL




B10
—
—
—
FAIL




B11
FAIL
PASS
—
FAIL




B12
PASS
FAIL
—
FAIL




B13
—
—
—
FAIL




B14
PASS
FAIL
—
FAIL




B15
PASS
FAIL
—
FAIL




B16
PASS
FAIL
—
FAIL




B17
PASS
FAIL
—
FAIL




B18
PASS
FAIL
—
FAIL




B19
PASS
FAIL
—
FAIL




B20
PASS
FAIL
—
FAIL




B21
PASS
FAIL
—
FAIL




B22
PASS
FAIL
—
FAIL




B23
PASS
FAIL
—
FAIL




B24
PASS
FAIL
—
FAIL




B25
PASS
FAIL
—
FAIL























TABLE 5-4











CHARPY
AMOUNT








ABSORBED
OF OXYGEN
Y-GROOVE
AMOUNT OF




YIELD
TENSILE
ENERGY
IN WELD
WELD
DIFFUSIBLE


WIRE

STRENGTH
STRENGTH
AT −196° C.
METAL
CRACKING
HYDROGEN


No.
CATEGORY
[MPa]
[MPa]
[J]
[ppm]
TEST
[ml/100 g]





B26
COMPARATIVE
729
782
41
87
—
—


B27
EXAMPLE
737
794
40
96
—
—


B28

747
807
42
104
—
—









B29

NOT EVALUATED DUE TO FREQUENTLY OCCURRENCE OF SPATTER


B30

NOT EVALUATED DUE TO OCCURRENCE OF WELD DEFECT














B31

734
782
35
84
—
—


B32

605
649
62
107
—
—


B33

820
871
44
100
—
—


B34

716
769
30
194
—
—


B35

722
774
33
205
—
—


B36

863
907
38
98
—
—


B37

794
843
23
108
—
—









B38

NOT EVALUATED DUE TO FREQUENTLY OCCURRENCE OF SPATTER














B39

755
845
35
158
CRACKING
2.2









B40

NOT EVALUATED DUE TO FREQUENTLY OCCURRENCE OF SPATTER


B41

NOT EVALUATED DUE TO UNSTABLE ARC


B42

NOT EVALUATED DUE TO UNSTABLE ARC


B43

NOT EVALUATED DUE TO BAD SLAG PEELABILITY














B44

740
795
42
150
—
—


B45

580
640
80
98
—
—


B46

715
761
35
175
—
—


B47

724
771
39
196
—
—


B48

698
744
37
168
—
—









B49

NOT EVALUATED DUE TO UNSTABLE ARC


B50

NOT EVALUATED DUE TO BAD SLAG PEELABILITY














B51

712
755
24
185
—
—




















COLD





WIRE
TENSILE

CRACKING
OVERALL




No.
STRENGTH
TOUGHNESS
RESISTANCE
DETERMINATION
REMARKS






B26
PASS
FAIL
—
FAIL




B27
PASS
FAIL
—
FAIL




B28
PASS
FAIL
—
FAIL




B29
—
—
—
FAIL




B30
—
—
—
FAIL




B31
PASS
FAIL
—
FAIL




B32
FAIL
PASS
—
FAIL




B33
PASS
FAIL
—
FAIL




B34
PASS
FAIL
—
FAIL




B35
PASS
FAIL
—
FAIL




B36
FAIL
FAIL
—
FAIL
ARC IS UNSTABLE AND








WELD BEAT IS INFERIOR



B37
PASS
FAIL
—
FAIL
ARC IS UNSTABLE AND








WELD BEAT IS INFERIOR



B38
—
—
—
FAIL
ARC IS UNSTABLE AND








WELD BEAT IS INFERIOR



B39
PASS
FAIL
—
FAIL




B40
—
—
—
FAIL




B41
—
—
—
FAIL
ARC IS UNSTABLE AND








WELD BEAT IS INFERIOR



B42
—
—
—
FAIL
ARC IS UNSTABLE AND








WELD BEAT IS INFERIOR



B43
—
—
—
FAIL
ARC IS UNSTABLE AND








WELD BEAT IS INFERIOR



B44
PASS
FAIL
—
FAIL




B45
FAIL
PASS
—
FAIL




B46
PASS
FAIL
—
FAIL




B47
PASS
FAIL
—
FAIL




B48
PASS
FAIL
—
FAIL




B49
—
—
—
FAIL




B50
—
—
—
FAIL




B51
PASS
FAIL
—
FAIL























TABLE 5-5











CHARPY
AMOUNT








ABSORBED
OF OXYGEN
Y-GROOVE
AMOUNT OF




YIELD
TENSILE
ENERGY
IN WELD
WELD
DIFFUSIBLE


WIRE

STRENGTH
STRENGTH
AT −196° C.
METAL
CRACKING
HYDROGEN


No.
CATEGORY
[MPa]
[MPa]
[J]
[ppm]
TEST
[ml/100 g]





A56
EXAMPLE
654
708
93
62
NO CRACKING
0.4


A57
EXAMPLE
652
695
97
51
NO CRACKING
0.6


A58
EXAMPLE
693
730
89
65
NO CRACKING
0.5


A59
EXAMPLE
690
736
92
56
NO CRACKING
0.4


A60
EXAMPLE
751
796
84
55
NO CRACKING
0.5


A61
EXAMPLE
763
802
72
75
NO CRACKING
0.5


A62
EXAMPLE
620
665
95
53
NO CRACKING
0.6


A63
EXAMPLE
757
828
79
59
NO CRACKING
0.4


A64
EXAMPLE
692
744
88
55
NO CRACKING
0.4


A65
EXAMPLE
687
732
85
69
NO CRACKING
0.5


A66
EXAMPLE
706
751
90
65
NO CRACKING
0.4


A67
EXAMPLE
685
736
73
57
NO CRACKING
0.5


A68
EXAMPLE
723
784
84
68
NO CRACKING
0.9


A69
EXAMPLE
729
790
79
63
NO CRACKING
0.4


A70
EXAMPLE
746
796
78
64
NO CRACKING
0.6


A71
EXAMPLE
735
786
80
55
NO CRACKING
0.5


A72
EXAMPLE
722
769
84
54
NO CRACKING
0.5


A73
EXAMPLE
734
777
80
55
NO CRACKING
0.6


A74
EXAMPLE
721
784
77
59
NO CRACKING
0.5


A75
EXAMPLE
719
769
93
42
NO CRACKING
0.4


A76
EXAMPLE
735
782
77
56
NO CRACKING
0.5


A77
EXAMPLE
749
794
88
49
NO CRACKING
0.4


A78
EXAMPLE
723
771
80
64
NO CRACKING
0.4


A79
EXAMPLE
745
789
79
65
NO CRACKING
0.5



















COLD




WIRE
TENSILE

CRACKING
OVERALL



No.
STRENGTH
TOUGHNESS
RESISTANCE
DETERMINATION






A56
PASS
PASS
PASS
PASS



A57
PASS
PASS
PASS
PASS



A58
PASS
PASS
PASS
PASS



A59
PASS
PASS
PASS
PASS



A60
PASS
PASS
PASS
PASS



A61
PASS
PASS
PASS
PASS



A62
PASS
PASS
PASS
PASS



A63
PASS
PASS
PASS
PASS



A64
PASS
PASS
PASS
PASS



A65
PASS
PASS
PASS
PASS



A66
PASS
PASS
PASS
PASS



A67
PASS
PASS
PASS
PASS



A68
PASS
PASS
PASS
PASS



A69
PASS
PASS
PASS
PASS



A70
PASS
PASS
PASS
PASS



A71
PASS
PASS
PASS
PASS



A72
PASS
PASS
PASS
PASS



A73
PASS
PASS
PASS
PASS



A74
PASS
PASS
PASS
PASS



A75
PASS
PASS
PASS
PASS



A76
PASS
PASS
PASS
PASS



A77
PASS
PASS
PASS
PASS



A78
PASS
PASS
PASS
PASS



A79
PASS
PASS
PASS
PASS























TABLE 5-6











CHARPY
AMOUNT








ABSORBED
OF OXYGEN
Y-GROOVE
AMOUNT OF




YIELD
TENSILE
ENERGY
IN WELD
WELD
DIFFUSIBLE


WIRE

STRENGTH
STRENGTH
AT −196° C.
METAL
CRACKING
HYDROGEN


No.
CATEGORY
[MPa]
[MPa]
[J]
[ppm]
TEST
[ml/100 g]





A80
EXAMPLE
681
720
86
59
NO CRACKING
0.6


A81
EXAMPLE
669
712
94
55
NO CRACKING
0.5


A82
EXAMPLE
701
743
88
64
NO CRACKING
0.6


A83
EXAMPLE
724
764
82
58
NO CRACKING
0.5


A84
EXAMPLE
764
805
78
65
NO CRACKING
0.4


A85
EXAMPLE
712
752
79
68
NO CRACKING
0.5


A86
EXAMPLE
694
735
80
63
NO CRACKING
0.5


A87
EXAMPLE
697
739
84
65
NO CRACKING
0.5


A88
EXAMPLE
695
740
75
75
NO CRACKING
0.5


A89
EXAMPLE
659
722
72
78
NO CRACKING
0.4


A90
EXAMPLE
666
726
73
76
NO CRACKING
0.4


A91
EXAMPLE
659
715
92
54
NO CRACKING
0.5


A92
EXAMPLE
671
724
87
59
NO CRACKING
0.6


A93
EXAMPLE
723
778
76
63
NO CRACKING
0.5


A94
EXAMPLE
729
789
79
60
NO CRACKING
0.5


A95
EXAMPLE
719
760
82
63
NO CRACKING
0.6


A96
EXAMPLE
702
765
79
70
NO CRACKING
0.4


A97
EXAMPLE
775
895
71
65
NO CRACKING
0.5


A98
EXAMPLE
692
798
82
56
NO CRACKING
0.6


A99
EXAMPLE
687
745
80
61
NO CRACKING
0.5


A100
EXAMPLE
708
786
78
68
NO CRACKING
0.4


A101
EXAMPLE
670
742
84
78
NO CRACKING
0.8


A102
EXAMPLE
658
752
72
76
NO CRACKING
0.7


A103
EXAMPLE
663
774
95
72
NO CRACKING
0.8


A104
EXAMPLE
710
831
79
76
NO CRACKING
0.6


A105
EXAMPLE
620
743
68
82
NO CRACKING
0.9


A106
EXAMPLE
643
782
78
72
NO CRACKING
1.0


A107
EXAMPLE
705
738
62
95
NO CRACKING
0.6


A108
EXAMPLE
663
694
69
79
NO CRACKING
0.6



















COLD




WIRE
TENSILE

CRACKING
OVERALL



No.
STRENGTH
TOUGHNESS
RESISTANCE
DETERMINATION






A80
PASS
PASS
PASS
PASS



A81
PASS
PASS
PASS
PASS



A82
PASS
PASS
PASS
PASS



A83
PASS
PASS
PASS
PASS



A84
PASS
PASS
PASS
PASS



A85
PASS
PASS
PASS
PASS



A86
PASS
PASS
PASS
PASS



A87
PASS
PASS
PASS
PASS



A88
PASS
PASS
PASS
PASS



A89
PASS
PASS
PASS
PASS



A90
PASS
PASS
PASS
PASS



A91
PASS
PASS
PASS
PASS



A92
PASS
PASS
PASS
PASS



A93
PASS
PASS
PASS
PASS



A94
PASS
PASS
PASS
PASS



A95
PASS
PASS
PASS
PASS



A96
PASS
PASS
PASS
PASS



A97
PASS
PASS
PASS
PASS



A98
PASS
PASS
PASS
PASS



A99
PASS
PASS
PASS
PASS



A100
PASS
PASS
PASS
PASS



A101
PASS
PASS
PASS
PASS



A102
PASS
PASS
PASS
PASS



A103
PASS
PASS
PASS
PASS



A104
PASS
PASS
PASS
PASS



A105
PASS
PASS
PASS
PASS



A106
PASS
PASS
PASS
PASS



A107
PASS
PASS
PASS
PASS



A108
PASS
PASS
PASS
PASS























TABLE 5-7











CHARPY
AMOUNT








ABSORBED
OF OXYGEN
Y-GROOVE
AMOUNT OF




YIELD
TENSILE
ENERGY
IN WELD
WELD
DIFFUSIBLE


WIRE

STRENGTH
STRENGTH
AT −196° C.
METAL
CRACKING
HYDROGEN


No.
CATEGORY
[MPa]
[MPa]
[J]
[ppm]
TEST
[ml/100 g]












B52
COMPARATIVE
NOT EVALUATED DUE TO UNSTABLE ARC


B53
EXAMPLE
NOT EVALUATED DUE TO A LOT OF FUME AND BAD WELDING EFFICIENCY


B54

NOT EVALUATED DUE TO UNSTABLE ARC














B55

722
775
62
106
—
—









B56

NOT EVALUATED DUE TO BAD SLAG PEELABILITY














B57

721
769
54
97
—
—


B58

758
804
79
62
CRACKING
1.9


B59

727
778
43
68
—
—


B60

744
789
64
93
—
—









B61

NOT EVALUATED DUE TO UNSTABLE ARC


B62

NOT EVALUATED DUE TO UNSTABLE ARC














B63

602
640
99
66
—
—


B64

816
884
55
72
—
—









B65

NOT EVALUATED DUE TO OCCURRENCE OF WELD DEFECT














B66

710
759
37
77
—
—


B67

702
746
48
72
—
—


B68

713
755
40
69
—
—


B69

749
801
29
64
—
—


B70

748
795
33
60
—
—


B71

716
762
53
79
—
—


B72

709
753
66
75
—
—


B73

700
746
52
74
—
—


B74

726
779
63
70
—
—


B75

753
804
65
65
—
—



















COLD




WIRE
TENSILE

CRACKING
OVERALL



No.
STRENGTH
TOUGHNESS
RESISTANCE
DETERMINATION






B52
—
—
—
FAIL



B53
—
—
—
FAIL



B54
—
—
—
FAIL



B55
PASS
FAIL
—
FAIL



B56
—
—
—
FAIL



B57
PASS
FAIL
—
FAIL



B58
PASS
PASS
FAIL
FAIL



B59
PASS
FAIL
—
FAIL



B60
PASS
FAIL
—
FAIL



B61
—
—
—
FAIL



B62
—
—
—
FAIL



B63
FAIL
PASS
—
FAIL



B64
PASS
FAIL
—
FAIL



B65
—
—
—
FAIL



B66
PASS
FAIL
—
FAIL



B67
PASS
FAIL
—
FAIL



B68
PASS
FAIL
—
FAIL



B69
PASS
FAIL
—
FAIL



B70
PASS
FAIL
—
FAIL



B71
PASS
FAIL
—
FAIL



B72
PASS
FAIL
—
FAIL



B73
PASS
FAIL
—
FAIL



B74
PASS
FAIL
—
FAIL



B75
PASS
FAIL
—
FAIL























TABLE 5-8











CHARPY
AMOUNT








ABSORBED
OF OXYGEN
Y-GROOVE
AMOUNT OF




YIELD
TENSILE
ENERGY
IN WELD
WELD
DIFFUSIBLE


WIRE

STRENGTH
STRENGTH
AT −196° C.
METAL
CRACKING
HYDROGEN


No.
CATEGORY
[MPa]
[MPa]
[J]
[ppm]
TEST
[ml/100 g]





B76
COMPARATIVE
762
818
61
60
—
—


B77
EXAMPLE
751
792
60
63
—
—


B78

716
762
44
72
—
—


B79

720
756
54
75
—
—


B80

726
782
62
76
—
—









B81

NOT EVALUATED DUE TO FREQUENTLY OCCURRENCE OF SPATTER


B82

NOT EVALUATED DUE TO OCCURRENCE OF WELD DEFECT














B83

671
729
41
74
—
—


B84

613
652
106
69
—
—


B85

804
858
62
76
—
—


B86

751
796
68
88
—
—


B87

712
759
61
106
—
—


B88

726
778
59
99
—
—


B89

675
805
42
65
—
—


B90

665
725
39
85
—
—


B91

780
905
30
60
—
—


B92

745
705
45
130
—
—


B93

710
720
32
123
—
—


B94

655
702
42
88
—
—


B95

680
720
37
98
—
—


B96

680
720
37
98
—
—


B97

591
712
32
102
—
—


B98

720
780
29
192
—
—


B99

712
759
28
185
—
—


B100

712
759
29
186
—
—









B101

NOT EVALUATED DUE TO UNSTABLE ARC



















COLD




WIRE
TENSILE

CRACKING
OVERALL



No.
STRENGTH
TOUGHNESS
RESISTANCE
DETERMINATION






B76
PASS
FAIL
—
FAIL



B77
PASS
FAIL
—
FAIL



B78
PASS
FAIL
—
FAIL



B79
PASS
FAIL
—
FAIL



B80
PASS
FAIL
—
FAIL



B81
—
—
—
FAIL



B82
—
—
—
FAIL



B83
PASS
FAIL
—
FAIL



B84
FAIL
PASS
—
FAIL



B85
PASS
FAIL
—
FAIL



B86
PASS
FAIL
—
FAIL



B87
PASS
FAIL
—
FAIL



B88
PASS
FAIL
—
FAIL



B89
PASS
FAIL
—
FAIL



B90
PASS
FAIL
—
FAIL



B91
FAIL
FAIL
—
FAIL



B92
PASS
FAIL
—
FAIL



B93
PASS
FAIL
—
FAIL



B94
PASS
FAIL
—
FAIL



B95
PASS
FAIL
—
FAIL



B96
PASS
FAIL
—
FAIL



B97
PASS
FAIL
—
FAIL



B98
PASS
FAIL
—
FAIL



B99
PASS
FAIL
—
FAIL



B100
PASS
FAIL
—
FAIL



B101
—
—
—
FAIL

















TABLE 6








MECHANICAL PROPERTY









CHARPY



ABSORBED












BASE
PLATE
CHEMICAL COMPOSITION OF STEEL PLATE
YIELD
TENSILE
ENERGY


METAL
THICKNESS
[mass %]
STRENGTH
STRENGTH
AT −196° C.






















No.
[mm]
C
Si
Mn
P
S
Ni
Al
Mo
N
O
Ceq
[MPa]
[MPa]
[J]





P1
25
0.06
0.2
0.6
0.002
0.001
9.12
0.04
0.01
0.004
0.001
0.40
675
725
178


P2
20
0.06
0.2
0.5
0.006
0.004
9.25
0.02
0.01
0.004
0.001
0.38
669
720
197









INDUSTRIAL APPLICABILITY
The gas-shielded arc welding capable of significantly reducing welding material costs and achieving excellent welding efficiency can be applied by reducing the amount of Ni of the flux-cored wire used for welding Ni-based steel for low temperature use containing about 5.5% to 9.5% of Ni to the same level as Ni-based steel for low temperature use. In addition, a weld metal having excellent low temperature toughness at −196° C. can be obtained by reducing the alloy composition of the flux filled in the wire to reduce the amount of oxygen in the weld metal. Further, it is possible to provide a flux-cored wire in which preheating for preventing cold cracking is not required or preheating can be significantly reduced. Therefore, the industrial value of the present invention is very high.
BRIEF DESCRIPTION OF THE REFERENCE SYMBOLS


    
    
        1: STEEL PLATE
        2: BACKING METAL
        3: WELD BEAD
        4: CHARPY IMPACT TEST PIECE (HAVING 2 MM V-NOTCH)
        5: A0 TEST PIECE (ROD) FOR TENSILE TEST

## Claims

1. A flux-cored wire for gas-shielded arc welding comprising:
an outer steel sheath; and
a flux with which the outer steel sheath is filled,
wherein one or more of CaF2, BaF2, SrF2, MgF2, and LiF, which are metal fluorides, are included in the flux-cored wire and, when a total amount thereof is defined as α, the α is 2.0% to 7.0%, by mass %, with respect to a total mass of the flux-cored wire,
one or more of a Ti oxide, a Si oxide, a Mg oxide, an Al oxide, a Zr oxide, and a Ca oxide, which are metal oxides, are included in the flux-cored wire and, when a total amount thereof is defined as β, the β is 0.2% to 0.9%, by mass %, with respect to the total mass of the flux-cored wire,
one or more of CaCO3, BaCO3, SrCO3, MgCO3, and Li2CO3, which are metal carbonates, are included in the flux-cored wire and a total amount thereof is less than 0.6%, by mass %, with respect to the total mass of the flux-cored wire,
a ratio of an amount of the CaF2 with respect to the α is 0.90 or more,
a ratio of the α with respect to the β is 3.0 or more and 15.0 or less,
an amount of the Ti oxide is 0% to 0.4%, by mass %, with respect to the total mass of the flux-cored wire,
an amount of the Si oxide is 0.2% to 0.5%, by mass %, with respect to the total mass of the flux-cored wire,
an amount of the Ca oxide is less than 0.20%, by mass %, with respect to the total mass of the flux-cored wire,
an amount of an arc stabilizer in the flux is 0% to 0.50%, by mass %, with respect to the total mass of the flux-cored wire,
an amount of an iron powder in the flux is less than 5%, by mass %, with respect to the total mass of the flux-cored wire,
chemical compositions except the metal fluorides, the metal oxides, and the metal carbonates include, by mass %, with respect to the total mass of the flux-cored wire,
C: 0.003% to 0.040%;
Si: 0.05% to 0.40%;
Mn: 0.2% to 0.8%;
Al: 0.003% to 0.050%;
Ni: 6.0% to 16.0%;
P: 0.02% or less;
S: 0.01% or less;
Cu: 0% to 0.5%;
Cr: 0% to 0.5%;
Mo: 0% to 0.5%;
V: 0% to 0.2%;
Ti: 0% to 0.1%;
Nb: 0% to 0.1%;
B: 0% to 0.01%;
Mg: 0% to 0.6%;
REM: 0 to 0.0500%; and
a remainder: Fe and an impurity,
a SM defined by expression a is 0.3% to 1.0%,
a Ceq defined by expression b is 0.250% to 0.525%,


SM=[Si]+[Mn]:  (Expression a),



Ceq=[C]+( 1/24)[Si]+(1⁄6)[Mn]+( 1/40)[Ni]+(1⁄5)[Cr]+(1⁄4)[Mo]+( 1/14)[V]:  (Expression b), and


in the Expressions a and b, elements noted in brackets express amounts (mass %) of the elements, respectively.

2. The flux-cored wire for gas-shielded arc welding according to claim 1, wherein the flux-cored wire includes the outer steel sheath including Ni and the flux filled therein, and
an amount of Ni in the outer steel sheath is 6% to 18%, by mass %, with respect to the total mass of the outer steel sheath.

3. The flux-cored wire for gas-shielded arc welding according to claim 1 or 2, wherein an amount of REM in the flux-cored wire is 0.0100% or less, by mass %, with respect to the total mass of the flux-cored wire.

4. The flux-cored wire for gas-shielded arc welding according to claim 1 or 2, wherein the amount of the CaO as the Ca oxide in the flux-cored wire is less than 0.10%, by mass %, with respect to the total mass of the flux-cored wire.

5. The flux-cored wire for gas-shielded arc welding according to claim 1 or 2, wherein a tensile strength of a weld metal is 660 MPa to 900 MPa in a tensile test to the weld metal regulated in Japanese Industrial Standards JIS Z 3111-2005 in the gas-shielded arc welding using the flux-cored wire.

6. The flux-cored wire for gas-shielded arc welding according to claim 1 or 2, wherein a slit-shaped gap does not exist in the outer steel sheath of the flux-cored wire.

7. The flux-cored wire for gas-shielded arc welding according to claim 1 or 2, wherein a slit-shaped gap exists in the outer steel sheath of the flux-cored wire.

8. The flux-cored wire for gas-shielded arc welding according to claim 1 or 2, wherein a perfluoropolyether oil is applied on a surface of the outer steel sheath of the flux-cored wire.

9. A method for welding steel for very low temperature use, wherein welding is performed with a flux-cored wire for gas-shielded arc welding and with any one of a pure Ar gas, a mixed gas of Ar and 1.5 volume % or less of O2 or CO2, a pure He gas, and a mixed gas of He and 1.5 volume % or less of O2 or CO2 as a shielding gas;
wherein the flux-cored wire for gas-shielded arc welding comprises:
an outer steel sheath; and
a flux with which the outer steel sheath is filled,
wherein one or more of CaF2, BaF2, SrF2, MgF2, and LiF, which are metal fluorides, are included in the flux-cored wire and, when a total amount thereof is defined as α, the α is 2.0% to 7.0%, by mass %, with respect to a total mass of the flux-cored wire,
one or more of a Ti oxide, a Si oxide, a Mg oxide, an Al oxide, a Zr oxide, and a Ca oxide, which are metal oxides, are included in the flux-cored wire and, when a total amount thereof is defined as β, the β is 0.2% to 0.9%, by mass %, with respect to the total mass of the flux-cored wire,
one or more of CaCO3, BaCO3, SrCO3, MgCO3, and Li2CO3, which are metal carbonates, are included in the flux-cored wire and a total amount thereof is less than 0.6%, by mass %, with respect to the total mass of the flux-cored wire,
a ratio of an amount of the CaF2 with respect to the α is 0.90 or more,
a ratio of the α with respect to the β is 3.0 or more and 15.0 or less,
an amount of the Ti oxide is 0% to 0.4%, by mass %, with respect to the total mass of the flux-cored wire,
an amount of the Si oxide is 0.2% to 0.5%, by mass %, with respect to the total mass of the flux-cored wire,
an amount of the Ca oxide is less than 0.20%, by mass %, with respect to the total mass of the flux-cored wire,
an amount of an arc stabilizer in the flux is 0% to 0.50%, by mass %, with respect to the total mass of the flux-cored wire,
an amount of an iron powder in the flux is less than 5%, by mass %, with respect to the total mass of the flux-cored wire,
chemical compositions except the metal fluorides, the metal oxides, and the metal carbonates include, by mass %, with respect to the total mass of the flux-cored wire,
C: 0.003% to 0.040%;
Si: 0.05% to 0.40%;
Mn: 0.2% to 0.8%;
Al: 0.003% to 0.050%;
Ni: 6.0% to 16.0%;
P: 0.02% or less;
S: 0.01% or less;
Cu: 0% to 0.5%;
Cr: 0% to 0.5%;
Mo: 0% to 0.5%;
V: 0% to 0.2%;
Ti: 0% to 0.1%;
Nb: 0% to 0.1%;
B: 0% to 0.01%;
Mg: 0% to 0.6%;
REM: 0 to 0.0500%; and
a remainder: Fe and an impurity,
a SM defined by expression a is 0.3% to 1.0%,
a Ceq defined by expression b is 0.250% to 0.525%,


SM=[Si]+[Mn]:  (Expression a),



Ceq=[C]+( 1/24)[Si]+(1⁄6)[Mn]+( 1/40)[Ni]+(1⁄5)[Cr]+(1⁄4)[Mo]+( 1/14)[V]:  (Expression b), and


in the Expressions a and b, elements noted in brackets express amounts (mass %) of the elements, respectively.

10. A method for manufacturing a weld joint, wherein a steel plate in which a thickness is 6 mm to 100 mm, an amount of Ni is 5.5 mass % to 9.5 mass %, and a tensile strength is 660 MPa to 900 MPa is welded with a flux-cored wire for gas-shielded arc welding and with any one of a pure Ar gas, a mixed gas of Ar and 1.5 volume % or less of O2 or CO2, a pure He gas, and a mixed gas of He and 1.5 volume % or less of O2 or CO2 as a shielding gas;
wherein the flux-cored wire for gas-shielded arc welding comprises:
an outer steel sheath; and
a flux with which the outer steel sheath is filled,
wherein one or more of CaF2, BaF2, SrF2, MgF2, and LiF, which are metal fluorides, are included in the flux-cored wire and, when a total amount thereof is defined as α, the α is 2.0% to 7.0%, by mass %, with respect to a total mass of the flux-cored wire,
one or more of a Ti oxide, a Si oxide, a Mg oxide, an Al oxide, a Zr oxide, and a Ca oxide, which are metal oxides, are included in the flux-cored wire and, when a total amount thereof is defined as β, the β is 0.2% to 0.9%, by mass %, with respect to the total mass of the flux-cored wire,
one or more of CaCO3, BaCO3, SrCO3, MgCO3, and Li7CO3, which are metal carbonates, are included in the flux-cored wire and a total amount thereof is less than 0.6%, by mass %, with respect to the total mass of the flux-cored wire,
a ratio of an amount of the CaF2 with respect to the α is 0.90 or more,
a ratio of the α with respect to the β is 3.0 or more and 15.0 or less,
an amount of the Ti oxide is 0% to 0.4%, by mass %, with respect to the total mass of the flux-cored wire,
an amount of the Si oxide is 0.2% to 0.5%, by mass %, with respect to the total mass of the flux-cored wire,
an amount of the Ca oxide is less than 0.20%, by mass %, with respect to the total mass of the flux-cored wire,
an amount of an arc stabilizer in the flux is 0% to 0.50%, by mass %, with respect to the total mass of the flux-cored wire,
an amount of an iron powder in the flux is less than 5%, by mass %, with respect to the total mass of the flux-cored wire,
chemical compositions except the metal fluorides, the metal oxides, and the metal carbonates include, by mass %, with respect to the total mass of the flux-cored wire,
C: 0.003% to 0.040%;
Si: 0.05% to 0.40%;
Mn: 0.2% to 0.8%;
Al: 0.003% to 0.050%;
Ni: 6.0% to 16.0%;
P: 0.02% or less;
S: 0.01% or less;
Cu: 0% to 0.5%;
Cr: 0% to 0.5%;
Mo: 0% to 0.5%;
V: 0% to 0.2%;
Ti: 0% to 0.1%;
Nb: 0% to 0.1%;
B: 0% to 0.01%;
Mg: 0% to 0.6%;
REM: 0 to 0.0500%; and
a remainder: Fe and an impurity,
a SM defined by expression a is 0.3% to 1.0%,
a Ceq defined by expression b is 0.250% to 0.525%,


SM=[Si]+[Mn]:  (Expression a),



Ceq=[C]+( 1/24)[Si]+(1⁄6)[Mn]+( 1/40)[Ni]+(1⁄5)[Cr]+(1⁄4)[Mo]+( 1/14)[V]:  (Expression b), and


in the Expressions a and b, elements noted in brackets express amounts (mass %) of the elements, respectively.

11. The flux-cored wire for gas-shielded arc welding according to claim 1, wherein an amount of REM in the flux-cored wire is 0.0100% or less, by mass %, with respect to the total mass of the flux-cored wire, and the amount of the CaO as the Ca oxide in the flux-cored wire is less than 0.10%, by mass %, with respect to the total mass of the flux-cored wire.

12. The flux-cored wire for gas-shielded arc welding according to claim 1 or 2, wherein an amount of Mn in the flux-cored wire is 0.2% to 0.7%, by mass %, with respect to the total mass of the flux-cored wire.