TREATMENT DEVICE, TREATMENT METHOD, METHOD FOR MANUFACTURING METAL PIPE MATERIAL, AND METAL PIPE MATERIAL

A treatment device that performs treatment for forming a plating layer on a metal pipe material that is used as a material for hot forming, the treatment device includes a supply unit that supplies a plating material to an inner periphery-side surface of a welded portion formed in the metal pipe material.

BACKGROUND

Technical Field

A certain embodiment of the present invention relates to a treatment device, a treatment method, a method for manufacturing a metal pipe material, and a metal pipe material.

Description of Related Art

In the related art, there is known a treatment device that performs treatment for forming a plating layer on a metal pipe material that is used as a material for hot forming. In this treatment device, a plating material is supplied to a welded portion of the metal pipe material from the outer periphery side (Al thermal spraying). Accordingly, in the treatment device, it is not possible to cover the outer periphery-side surface of the welded portion with a plating layer.

SUMMARY

According to an aspect of the present invention, there is provided a treatment device that performs treatment for forming a plating layer on a metal pipe material that is used as a material for hot forming, the treatment device including a supply unit that supplies a plating material to an inner periphery-side surface of a welded portion formed in the metal pipe material.

According to another aspect of the present invention, there is provided a treatment method for performing treatment for forming a plating layer on a metal pipe material that is used as a material for hot forming, the treatment method including a process of supplying a plating material to an inner periphery-side surface of a welded portion formed in the metal pipe material.

According to still another aspect of the present invention, there is provided a metal pipe material manufacturing method for manufacturing a metal pipe material from a plate material with a plating layer formed thereon, the method including performing, after end portions of the plate material are joined together by welding, plating treatment on a location where the plating layer has been peeled off due to the welding, of an inner peripheral surface of the metal pipe material.

According to still another aspect of the present invention, there is provided a metal pipe material that is used as a material for hot forming, and in which an inner periphery-side surface of a welded portion is covered with a plating layer.

DETAILED DESCRIPTION

A treatment device such as that of the related art described above can cover the surface of the welded portion with a plating layer from the outer periphery side. However, it is not possible to form a plating layer on the inner periphery-side surface of the welded portion. Accordingly, the inner periphery-side surface of the welded portion is exposed, so that there is a possibility that oxide scale may be generated on the surface.

It is desirable to provide a treatment device, a treatment method, a method for manufacturing a metal pipe material, and a metal pipe material, in which it is possible to manufacture a metal pipe material in which the generation of oxide scale can be suppressed.

The treatment device includes the supply unit that supplies the plating material to the inner periphery-side surface of the welded portion formed in the metal pipe material. In this way, the inner periphery-side surface of the welded portion of the metal pipe material is covered with the plating layer formed of the plating material. In this way, the welded portion can be prevented from being exposed on the inner periphery side of the metal pipe material. With the above, it is possible to manufacture the metal pipe material in which the generation of oxide scale can be suppressed.

The treatment device may further include a cutting unit provided on an upstream side of a location to which the plating material is supplied by the supply unit, in a feed direction of the metal pipe material, to cut the welded portion from an inner periphery side of the metal pipe material. In this case, after an excess portion on the inner periphery side of the welded portion is removed by the cutting unit, the supply unit can immediately form a plating layer on the inner periphery-side surface of the welded portion.

According to this treatment method, the same operation and effect as those of the treatment device described above can be obtained.

According to the method for manufacturing a metal pipe material, even in a case where the plating layer is peeled off due to joining the end portions of the plate material together by welding, the peeled location can be covered with the plating layer again by performing plating treatment on the peeled location. With the above, it is possible to manufacture the metal pipe material in which the generation of oxide scale can be suppressed.

According to this metal pipe material, the same operation and effect as those of the treatment device described above can be obtained.

Hereinafter, a preferred embodiment of the present invention will be described with reference to the drawings. In each drawing, identical or corresponding portions are denoted by the same reference numerals, and overlapping description is omitted.

FIG.1is a schematic configuration diagram showing a schematic configuration of a metal pipe material manufacturing apparatus100in which a treatment device50according to an embodiment of the present invention is adopted. The metal pipe material manufacturing apparatus100is an apparatus for manufacturing a metal pipe material that is used as a material for hot forming. As the hot forming that is used for a metal pipe material, for example, expansion forming can be given in which forming and quenching are simultaneously performed by placing a heated metal pipe material in a die and expanding it. In addition, hot forming such as induction quenching, hot bending forming, and hot drawing can be given.

Here, a metal pipe material20will be described with reference toFIG.6andFIGS.7A to7C.FIG.6is a perspective view of the metal pipe material20according to the present embodiment.FIGS.7A to7Care schematic diagrams for describing the states of a plating layer formed on the metal pipe material20. As shown inFIG.6, the metal pipe material20has a welded portion15called a weld bead or the like, in which end portions14aand14aof a plate material14are welded together. More specifically, the metal pipe material20is formed by rounding a flat plate-shaped metal plate material14into a cylindrical shape and welding the opposite end portions14aand14atogether in a state of being abutted against each other. The welded portion15in which the metal pipe material20is welded in this manner extends along a central axis L of the metal pipe material20. The central axis L of the metal pipe material20is parallel to an extending direction D of the metal pipe material20.

FIG.7Ais a diagram showing the metal pipe material20as viewed from an axial direction.FIG.7Bis an enlarged diagram showing the state of the vicinity of the welded portion15in a step before forming a plating layer.FIG.7Cis an enlarged diagram showing the state of the vicinity of the welded portion15in a state where the plating layer has been formed.FIGS.7B and7Care enlarged diagrams of an area surrounded by a dashed line circle inFIG.7A. As shown inFIGS.7B and7C, a plating layer16is formed on the outer peripheral surface of the metal pipe material20so as to cover the entire outer peripheral surface. Further, a plating layer17is formed on the inner peripheral surface of the metal pipe material20so as to cover the entire inner peripheral surface. The plating layers16and17are originally formed on both surfaces of the plate material14in a step before the plate material14is rounded into a cylindrical shape. The plating layers16and17are formed by performing, for example, AlSi plating treatment on the plate material14, which is a steel sheet.

As shown inFIG.7B, immediately after the welded portion15is formed, a state is created where the plating layers16and17that have been originally present are peeled off at the location of the welded portion15. That is, the location of the welded portion15, of the outer peripheral surface of the metal pipe material20, is a location where the plating layer16is peeled off due to welding. At this location, an outer periphery-side surface15aof the welded portion15is exposed. The location of the welded portion15, of the inner peripheral surface of the metal pipe material20, is a location where the plating layer17is peeled off due to welding. At this location, an inner periphery-side surface15bof the welded portion15is exposed.

On the other hand, in the metal pipe material20pertaining to a finished product, as shown inFIG.7C, the outer periphery-side surface15aof the welded portion15is covered with a plating layer18. The inner periphery-side surface15bof the welded portion15is covered with a plating layer19. The plating layers18and19are formed to extend along the longitudinal direction of the metal pipe material20so as to fill the gaps of the plating layers16and17. The plating layer18on the outer periphery side is formed by performing Al thermal spraying on the surface15aof the welded portion15from the outer periphery side of the metal pipe material20. The plating layer19on the inner periphery side is formed by the plating treatment using the treatment device50which will be described later.

It returns toFIG.1, and the metal pipe material manufacturing apparatus100is described. As shown inFIG.1, the metal pipe material manufacturing apparatus100includes a plate material supply device1, a forming device2, a welding device3, the treatment device50, and a cutting device4. The plate material supply device1is a device for supplying the plate material14(refer toFIG.6andFIGS.7A to7C), which is a precursor of the metal pipe material20. The plate material supply device1supplies the plate material14in a flat plate state to the forming device2. The plate material supply device1supplies the plate material14by rotating a roll body formed by winding a belt-shaped plate material14into a roll shape. The forming device2is a device for forming the plate material14into a cylindrical shape. The forming device2rounds the flat belt-shaped plate material14to form it in a cylindrical shape such that the end portions14aand14ain the width direction of the belt-shaped plate material14are abutted against each other.

The welding device3is a device that welds the abutting portions of the end portions14aand14aof the rounded plate material14to each other. In this way, the welded portion15is formed along the longitudinal direction. The welding device3forms the welded portion15by, for example, irradiating a welded location with a high frequency or the like. There is a case where the welded portion15immediately after welding swells in the thickness direction from the inner peripheral surface or the outer peripheral surface of the metal pipe material20(for example, refer toFIG.4(described later)). Therefore, the welding device3includes a cutting mechanism for cutting the swelled portion of the welded portion15immediately after welding.

The treatment device50is a device that forms the plating layers18and19by performing plating treatment on the location of the welded portion15. The treatment device50includes a mechanism for forming the plating layer18on the outer periphery side, and a mechanism for forming the plating layer19on the inner periphery side. Details of the mechanism for forming the plating layer19on the inner periphery side will be described later. The cutting device4is a device for cutting the metal pipe material20to a desired length. By cutting with the cutting device4, the metal pipe material20as shown inFIG.6is completed.

Next, a specific configuration of the treatment device50will be described with reference toFIGS.2A to2C.FIG.2Ais a schematic sectional view showing a state of the treatment device50in a state of being disposed inside the metal pipe material20.FIG.2Bis a sectional view taken along line IIb-IIb ofFIG.2A.FIG.2Cis a sectional view taken along line IIc-IIc ofFIG.2A.FIGS.2A to2Cshow an inner periphery-side plating layer forming mechanism51for forming the plating layer19on the inner periphery side, of the treatment device50. A mechanism for forming the plating layer18on the outer periphery side, of the treatment device50, is omitted. InFIGS.2A to2C, the plating layer19is shown to be thicker than the other plating layers in a deformed state.

As shown inFIG.2A, the inner periphery-side plating layer forming mechanism51of the treatment device50includes a rod52, a roller53, and a supply unit54. The plating layer forming mechanism51is disposed in an internal space SP on the inner periphery side of the metal pipe material20. The metal pipe material20is disposed such that the longitudinal direction thereof is parallel to the horizontal direction. Further, the metal pipe material20is sent in a feed direction D1in a state where the welded portion15is disposed on the upper end side. Here, the plating layer forming mechanism51is fixed so as not to move in the internal space of the metal pipe material20. Therefore, the metal pipe material20moves toward the feed direction D1, so that the metal pipe material20moves relative to the plating layer formation mechanism51.

As shown inFIGS.2A and2B, the rod52is disposed parallel to the longitudinal direction of the metal pipe material20within the internal space SP of the metal pipe material20. The rod52is disposed on the lower end side of the internal space SP and disposed on the inner peripheral surface of the lower end portion of the metal pipe material20through the roller53. In this way, when the metal pipe material20is sent in the feed direction D1, the roller53rotates while guiding the metal pipe material20in the feed direction D1. The rod52is configured with a cylindrical member.

As shown inFIG.2A, the supply unit54supplies a plating material58for forming the plating layer19to the inner periphery-side surface15bof the welded portion15formed in the metal pipe material20. In the present embodiment, the supply unit54supplies Al paint as the plating material58. Specifically, the supply unit54includes a supply pipe56that supplies the plating material58, and an injection nozzle57that injects the plating material58. The supply pipe56extends parallel to the longitudinal direction of the rod52within the rod52. The plating material58flows toward the injection nozzle57side in the supply pipe56. The injection nozzle57injects the plating material58supplied from the supply pipe56toward the welded portion15on the upper side. The injection nozzle57is connected to the supply pipe56at the end portion in the longitudinal direction of the rod52. The injection nozzle57extends so as to be curved upward from the end portion of the supply pipe56. In this way, as shown inFIG.2C, the plating material58is applied to the inner periphery-side surface15bof the welded portion15, and the plating material58is dried to form the plating layer19.

As the plating material58that is supplied by the supply unit54, for example, paint obtained by mixing fine particles of Al and Si in an organic solvent may be adopted. In this paint, the organic solvent volatilizes in a heating process, and the remaining Al and Si components remain on the surface of an iron base material, so that it is possible to form a plating layer that can suppress the generation of oxide scale, like an AlSi plating material.

Next, the operation and effect of the treatment device50, a treatment method, a method for manufacturing the metal pipe material20, and the metal pipe material20according to the present embodiment will be described.

The treatment device50includes the supply unit54that supplies the plating material58to the inner periphery-side surface15bof the welded portion15formed in the metal pipe material20. In this way, the inner periphery-side surface15bof the welded portion15of the metal pipe material20is covered with the plating layer19formed of the plating material58. In this way, the welded portion15can be prevented from being exposed on the inner periphery side of the metal pipe material20. With the above, it is possible to manufacture the metal pipe material20in which the generation of oxide scale can be suppressed.

The treatment method is a treatment method of performing treatment for forming the plating layer19on the metal pipe material20that is used as a material for hot forming, the treatment method including a process of supplying the plating material58to the inner periphery-side surface15bof the welded portion15formed in the metal pipe material20.

According to this treatment method, the same operation and effect as those of the treatment device50device described above can be obtained.

The metal pipe material manufacturing method is a method for manufacturing the metal pipe material20from the plate material14with the plating layer17formed thereon, the method including performing, after the end portions14aand14aof the plate material14are joined together by welding, plating treatment on a location where the plating layer17has been peeled off due to the welding, of the inner peripheral surface of the metal pipe material20.

According to the method for manufacturing the metal pipe material20, even in a case where the plating layer17is peeled off due to joining the end portions14aand14aof the plate material14together by welding, the peeled location can be covered with the plating layer19again by performing plating treatment on the peeled location. With the above, it is possible to manufacture the metal pipe material20in which the generation of oxide scale can be suppressed. Further, it is possible to manufacture the metal pipe material20having high rust prevention performance.

As a method of preventing oxide scales, there is also a method of applying antirust paint to the entire bare metal pipe material20. However, in this method, it is difficult to evenly apply a plating material to the inner and outer surfaces, and the cost also increases. In contrast, the treatment device50of the present embodiment performs treatment in a manner of repairing a partial location where the plating layer has been peeled off, and therefore, reliability is high, and the number of processes is not increased, so that the degree of increase in cost can also be kept small.

The metal pipe material20is the metal pipe material20that is used as a material for hot forming, and in which the inner periphery-side surface15bof the welded portion15is covered with the plating layer19.

According to the metal pipe material20, the same operation and effect as those of the treatment device50device described above can be obtained.

The present invention is not limited to the embodiment described above.

For example, the direction in which the injection nozzle57of the supply unit54supplies the plating material58is not particularly limited, and the treatment device50as shown inFIGS.3A to3Cmay be adopted.FIG.3Ais a schematic sectional view showing a state of the treatment device50according to a modification example in a state of being disposed inside the metal pipe material20.FIG.3Bis a sectional view taken along line IIIb-IIIb ofFIG.3A.FIG.3Cis a sectional view taken along line IIIc-IIIc ofFIG.3A. In the treatment device50as shown inFIGS.3A to3C, the injection nozzle57supplies the plating material58downward. Accordingly, the welded portion15of the metal pipe material20is also disposed on the lower end side of the metal pipe material20. As shown inFIG.3B, a pair of rollers53are provided with the welded portion15interposed therebetween when viewed in the axial direction on the lower end side of the rod52such that the rollers53and the welded portion15do not interfere with each other.

Further, the treatment device50as shown inFIG.4andFIGS.5A to5Dmay be adopted.FIG.4is a schematic sectional view showing a state of the treatment device50according to a modification example in a state of being disposed inside the metal pipe material20.FIG.5Ais a sectional view taken along line Va-Va ofFIG.4.FIG.5Bis a sectional view taken along line Vb-Vb ofFIG.4.FIG.5Cis a sectional view taken along line Vc-Vc ofFIG.4.FIG.5Dis a sectional view taken along line Vd-Vd ofFIG.4.

As shown inFIG.4, the treatment device50further includes a cutting unit59that is provided on the upstream side of the location to which the plating material58is supplied by the supply unit54, in the feed direction D1of the metal pipe material20, to cut the welded portion15from the inner periphery side of the metal pipe material20. In this case, after an excess portion15don the inner periphery side of the welded portion15is removed by the cutting unit59, the supply unit54can immediately form the plating layer19on the inner periphery-side surface15bof the welded portion15.

As shown inFIG.4, a welding nozzle60of the welding device3irradiates the outer periphery side of the metal pipe material20with a high frequency or the like, so that the abutted end portions14aand14aof the plate material14(refer toFIG.5A) are welded at a welding point WP. The position of the welding nozzle60is fixed in the feed direction D1. In this way, the upstream side of the welding point WP in the feed direction D1becomes a region where the welded portion15is not formed, and the downstream side of the welding point WP in the feed direction D1becomes a region where the welded portion15is formed. Here, immediately after the welding is performed at the welding point WP, the welded portion15has the excess portion15dhaving an excess thickness on the inner periphery side (also refer toFIG.5B). On the other hand, the cutting unit59is disposed at a position spaced from the welding point WP to the downstream side in the feed direction D1. The cutting unit59is configured with a blade member or the like, which protrudes upward from the upper end portion of the rod52. In this way, the cutting unit59can cut the excess portion15dprotruding toward the inner periphery side of the welded portion15. In this way, the inner periphery-side surface15bof the welded portion15is formed (also refer toFIG.5C). The injection nozzle57injects the plating material58at a position spaced from the cutting unit59to the downstream side in the feed direction D1. In this way, the plating layer19is formed on the surface15bafter cutting (also refer toFIG.5D).

Further, in the embodiment described above, a pipe-making apparatus in which the metal pipe material20is subjected to the plating treatment by the treatment device50after the welding device3and then is cut by the cutting device4has been described. However, the timing at which the treatment device50performs the plating treatment is not particularly limited. For example, after welding by the welding device3, the metal pipe material20may be cut by the cutting device4and then subjected to the plating treatment by the treatment device50. In this case, even in a case where it is difficult to install a new pipe-making apparatus or a case where it is difficult to modify an existing pipe-making apparatus, the treatment device50may be installed to a pipe-making apparatus in a retrofitting manner, so that there is an advantage that an existing pipe-making apparatus can be used as it is.

In the embodiment and modification examples described above, the supply unit54supplies the plating material58by using the injection nozzle57. The supply unit54may include a coating roller157instead of the injection nozzle57, as shown inFIGS.8,9, and10. Specifically,FIG.8is a diagram showing a structure in which the coating roller157is applied to the treatment device50shown inFIG.2A. As shown inFIG.8, the coating roller157is provided at the end portion of the rod52. The coating roller157is a cylindrical member that is supported to be rotatable with a rotary shaft158as the center. The rotary shaft158is fixed to the rod52. The coating roller157is not fixed with respect to the rod52. Therefore, the coating roller157rotates around the rotary shaft158at the end portion of the rod52.

A portion of an outer peripheral surface157aof the coating roller157is disposed at a position that is outside the rod52and close to the inner periphery-side surface15bof the welded portion15. Another portion of the outer peripheral surface157aof the coating roller157is disposed at a position in the rod52. The supply pipe56extends within the rod52to a position close to the outer peripheral surface157aof the coating roller157. In this way, the supply pipe56can supply the plating material58to the outer peripheral surface157aof the coating roller157within the rod52. When the metal pipe material20is fed in the feed direction D1, the coating roller157rotates. As a result, the plating material58supplied from the supply pipe56adheres to the inner periphery-side surface15bof the welded portion15as the outer peripheral surface157arotates.

FIG.9is a drawing showing a configuration in which the coating roller157is applied to the treatment device50shown inFIG.3A.FIG.10is a drawing showing a configuration in which the coating roller157is applied to the treatment device50shown inFIG.4. Each of the treatment devices50shown inFIGS.9and10includes the coating roller157and the supply pipe56having the same configuration as inFIG.8.