ADDITIONAL AGENT FOR UNDERWATER ARC-WELDING

Abstract: A pastellike additive used in the underwater arc welding to protect the weld and/or welding rod against the harmful effects of water. The additive contains the base material advantageously mixed with oily carrier liquid and comprising at least 10 percentages of weight one base material, advantageously a biomass with plenty of organic compounds, and possibly termitic agent, regulating agent for the pH-value of the additive, lighting agent, hydrogen removal agent and an agent to enhance the sufficiency. The additive according to the invention is characterized in that the ashless dry material of the biomass in the base material contains: 1...40, advantageously 10...13, percentages of weight amino acids; 0,5...10, advantageously 1,5...2,5, percentages of weight fatty acids; 50...98, advantageously 83...87, percentages of weight carbohydrates, preferably carbon compounds with large molecular sizes; and about 0,5 percentages of weight mineral substances and/or trace elements.

Description: ADDITIONAL AGENT FOR UNDERWATER ARC-WELDING This invention relates to the additive according to the preamble of the claim 1 being adaptable for use espe- cially in underwater arc welding. Enterprises making welding works and manufacturing welding devices and equipment have atrived to produce an arc welding method and equipment, by which the welding process and the end result would not be affec¬ ted by outer conditions. It is ' well-known in the art that arc welding - particularly in good conditions very easy-to-use protective arc welding - cannot suc- cesfully be performed in windy, draughty, rainy and/or wet surroundings let alone underwater conditions. Underwater welding has in recent years bee an object of ever-increasing interest and development work. Re¬ pairs and servicing of drilling platforms, particularly their underwater supporting structures and gas and/or oil pipes, ships and dock structures and equipment are the objects, in which underwater welding has primarily been used. The structures to be welded are generally such, that their lifting to the water surface is impos- sible or becomes very costly. The objective in under¬ water welding, as well as in welding generally, is and always will be the achievement of the highest quality welds. The known methods for underwater welding are divided on grounds of the welding conditions into two main groups: wet methods and dry methods. In the known wet methods in the rod welding mainly usual welding rods are used coated by water-tight vinyl paint or paraffin to prevent wetting, and in gas arc welding besides the conven¬ tional equipment also a welding device, in which a from the ou¬ ter perimeter of the nozzle directed conical water jet keeps the arc area separated from the water. Water jet has been used with relatively good results in the carbon dioxide wet method. In wet methods water may come, as even the name implies, unhin- dered to the arc area. In the dry methods the access of water to the arc area is prevented by covering the arc area with an essentially closed (weldable seam is naturally free) or at the lower end open opaque or transparent welding shield. The weld¬ ing device is brought to the welding shields open at their lo¬ wer end usually from below or to the entirely closed welding shields through the wall. If the welding shield is sufficiently large, the welder may work inside the shield. The welding shi- elds are provided with either a protective gas or air atmos¬ phere. In underwater welding the welds of almost the same quality are achieved as in welding performed in favourable conditions above the ground level. The drawbacks in dry methods are, however, the time-consuming mountings and transfers of welding shields and also the inconvenience and inflexibility of the welding work due to the use of shields. There are also many places, where the use of welding shield is impossible. Wet wel.ding, to which the" present invention is particularly connected, is a rather flexible and economic system for underwater welding works It can, if the welding is performed manually, be carried out except the diving equipment by the same devices as welding above the groun level. The weld quality in wet methods has not been even nearly as good as in the dry welding methods. Mainly be¬ cause of this fact various classification institutions have not accepted the use of wet methods in the objects under their ins¬ pection. Three problems appear in the wet welding and all of them are caused by the surrounding water. They comprise a high cooling rate, high hydrogen content and the ambient pressure influencing to the reactions in the arc and also to the trans¬ fer of material as well as to the reactions between the melt and the slag especially in deeper depths. The worst problem in wet methods is the appearance of hydrogen cracks. It is expressly caused by the large amount of hydrogen in the welding seam. High cooling rate makes further diffusion of water more diffi¬ cult from the welding seam, and pre- or afterheatings cannot be used in practice to remove the hydrogen, to reduce strains or to avoid fragile microstructure. As a result of the high cooling rate a mostly easily brittling and great inner tensions comprising micro¬ structure is produced in structural steels. Another significant problem in wet methods is the poor impact strength of the welding seam. Ambient pressure, especially in greater depths, changes the conditions of slag reactions, and swift cooling does not give kinetic preconditions for sufficient cleaning of the welding material. Particularly in rod welding the avoidance of welding faults, such as slag enclosures in pores, slag line and joint or root faults by wet methods calls for special professional skill in difficult conditions. The above-mentioned problems connected with wet welding have been tried.to solve heretofore by different protec¬ tive substances applied to the weldable object, but not with even satisfactory results. These previously known substances are among other things the paste according to the FI Patent No. 800248 consist¬ ing of the base material, such as soap, pine soap or equivalent- and mixed with an electrically, conductive fine powder;' protective paste- according to" the FI Patent No. ' 67188 comprising a base material mixed with glyceri- ne and including 40-50 percentages by weight oil acid and 1-40 percentages by weight linoleic acid, and pos¬ sibly a lighting agent and a hydrogen removal agent, which are f.ex. magnesium as a lighting and hydrogen removal agent, iron oxide as a hydrogen removal- agent or amorphous phosphorus as a lighting agent; the fast or semifast pastelike agent according to the FI Patents No. 780282 and 780283, which as at least partially dis¬ solved in water forms an electrolyte and contains metal, non-metal etc. salt of an organic or inorganic acid, advantageously alkali salts of fat acids, soap or soft soap. The objective of the present invention is to eliminate the above-mentioned disadvantages essential to the wet welding and their consequences better than before and to achieve a new additive suitable to be used espe¬ cially for arc welding performed in water. This objec¬ tive has been attained by the additive according to the invention, which is characterized by the characteristic features mentioned in the appended claims. By the additive to be introduced to the arc area it is strived to facilitate the controlled burning of the arc, enhance the weld melt, delay the cooling of the weld and ■ limit the direct presence of water in the arc area- and also the contact to the weld melt. Because of the additive according to the invention the ignition of the arc takes place easie and the- arc is stabilized. ' It forms a protective gas zone to the arc et H3 S3 0 ) ι-3 rt 3" Hi rt H β σ σ HI Ω » rt σ cn OJ 3 * 3 * Φ H 3 * tr •< 3 * 3 * 0 cn *< Φ β o Φ 3 * β β 3 Φ Φ Φ i- H φ φ OJ Φ Φ C-_ φ cn H H 0> Φ H σ Oi * α. H C rt H- H Ωi cn H 3 cn S Φ H- 0 ) t s o S3 cn 3 * 3 * α ► H- 0 3 H" rt •0 ι-3 Φ Λ 3 H Di Φ ua to Φ Φ tu Φ Φ 3 3 J 3 OJ Φ 3 * H C cΩ O a H Φ \-* t to α cn ?T lΩ cn H ιΩ 3 3 Φ 0- H- • * H- α 3 α 3 rt O Φ 3 Ω Φ H- •o OJ rt H- H- H rt O rt Hi Φ H- φ rt OJ 3 3 s 3 H- H- σ H £ 3 rt Φ 3" s 0 0 3 3 cn t-t Ωi en Φ H α < 01 H φ H- *Ω H- Ω φ 3 H Φ OJ Ω_ 3 cr. Φ H- 3 rt < rt ■ rt l-t rt 0 rt H « TJ rt 1 ιQ 3 rt o - rt Φ H cn 3" rt cΩ 3 * H. H- rt φ 0J 0J 0 ) rt r- 1 - 3" H- H- Φ 3 * : Φ o H- 11 OJ CO Ω α H 3 OJ Φ σ Ω 3 * Φ • 0 3 < Hi 3 ■ s Ω Φ H- cn G. Φ Φ Φ H- 0) n ^ Φ o Qi 5 to o 3 Oi 0 rt cn 3 Φ H cΩ n a n H cn ιQ 3 H- σ t. - Φ O < X Ω t 33 H- 3 3 \ Ω α rt O rt l_i. φ Hi et Φ Ω 3 3 * 3 OJ Φ ^ H- H rt 32 H- Φ φ Φ Hi 3 * 3 Φ Ω. H- H- Hi 3 rr £ 3 O 3- 0 Ω 3 φ Φ rt H Φ Ω Ω M O £T H Φ ιQ 3 Φ 3 rt Ω Ω H H- H < cr β Φ 0 M H 03 o to ^ rt β rt o Φ Φ O Φ • 0 Ω Qι rt Φ 32 3 H 3 * H Hi 3 3 H n OJ 3 cn 1 H- ^ 0 H Φ cΩ rt Φ H o t rt 0 H- H Ω 3 H Φ cn 3" Φ Hi Ω H- *XJ vQ Φ Φ 3 cQ rt rt l-l Φ £ 3 rt 3 Hi H- CO tl OJ XX 3 * OJ 3 * rt rt 0 β OJ 3 H « rt n to Φ CD σ 3* a s2 O n 3" H β 3 3 OJ C o •σ 3 Φ 0 to Φ 3 Ω H 0J Ό H < H D> •α H- Ω rt OJ et Φ ιQ Ωi Ωi rt Φ H H cn 0» et H 3 σ o * * 3 Φ Φ OJ Φ Φ H- 3 φ 0 o H o H- < Φ 3 Oi H 3 Ω. H 0 0J < H 3 o Φ H) Φ 32 Φ Φ Ωι 0 ) s: 3 H β φ rt *< Φ > 3 0 cn 3 * cn H- H n H- ►< 0 ) ?r cn Ωi o rt rt H Φ H 3 DJ a H- rt O 0 ) φ I i < to H> P- .Φ 1-5 flJ tu ft H- 3 φ Hi σ α Φ et • i OJ 3 0 O • o Φ ιQ < σ φ < ifl 1-1 * cn XT H Cb 3 3 n i σ H- H Q- Φ rt φ Ό Φ • CO Φ •< H Ω Φ rt 32 3 * S3 Φ Ό ^ Hi 0 ) H- σ 3 3" φ Φ 0J 3" Ω 3 Ωi i-* H- Φ rt K: 3 0 φ to Φ H» 3 H- H- φ Φ OJ (0 rt Hi * Φ H- σ Ω < Oi to 0 Ω OJ I- 1 • •0 in β cn Hi Φ H rt l_l. 01 £ H- α β 3- M rt φ 3 Ω Φ cn « φ β cr Φ 3 Ωi 3 H- 3 3 * Hi Ω H Ω cn Φ H ιΩ H- rt S3 ► 3 Qi S3 O rt Φ rt 0 rt φ Ωi rt 3" ifl H- Φ 0J H H- 3 3 * Hi Ω OJ H- O Φ 32 3 H cn < O Φ to O £u Ω H < Hi 3 3" H cΩ Ω. c Φ < H .H- 3 Hi β O Φ Φ φ OJ H- H cn to Φ rt α cn o 3 rt o 3 • 0 φ 0J \-* 0 rt φ H 3 OJ Φ 3 cΩ a. 3 Hi OJ rt 3 * H- O Ω ' • CL. O • 3 " Φ 3 rt 1 3 Hi __ Φ In the following mainly the. underwater welding is described, because the problems in the arc welding performed in- water- are at the present the greatest. By the use of " the- additive according to the invention it is however possible to perform- arc welding also in different outer conditions, e.g. in connection with the arc welding above the ground level. In this case the additive- according to the invention prevents besides the water the harmful effect of air to the weld. When the additive according to the invention is used in circumstances above the ground level for arc welding, more combustion gases are formed than in the underwater welding. The invention is thus based on the arrangement in which the conventional protective gas or coating " of the welding rod has been replaced by the additive, the purpose of which is to stabilize the burning in the arc, facilitate the ionization of the arc area and protect both the arc and the produced weld against the harmful effects of environmental con- ditions. The additive according to the invention fits for use in connection with arc weldings performed both under water and above the ground level protecting the arc and the weld. A substantial advantage of the inven¬ tion is also the possibility, that by changing the a- terial contents of the additive it can be adjusted as a basic or acid substance., so that it always fits for the environmental conditions. The methods of use of the additive according to the in- vention are now described with reference to the accom¬ panying drawing. In Fig..1 the arc.1 is formed between the welding rod 9 and the base material 13. At the same time the weld- ing rod 9 melts and forms the weld seam.10, which is melted fast to the base material.13. When the weld.10 is forme a slag layer 11 is generated from the coat¬ ing of the welding rod 9 on the weld. The additive 2 according to the invention is introduced to the arc area 2. In the application of Fig. 2 the additive according to the invention is introduced to the arc area 1 from an annular nozzle 4 surrounding the arc and the welding rod 9. This arrangement resembles the protective arc welding (MIG, TIG, MAG) . The only difference is that instead of the protective gas now the additive accord¬ ing to the invention is used, which has advantageous pastelike properties. The additional use of the protec¬ tive gas is, of course, possible. In Fig. 3 has been shown an application, in which the arc area formed between the welding rod 9 and base ma- terial 13 is partly protected by the additive according to the invention. Welding takes place under water and water surrounds the welding object. When welding is progressing the additive 3 is carried behind the arc and the weld is produced, when the arc burns in the cavity 7 formed in the additive 3. Also a protective layer 8 is separated from the additive 3 on the weld.10 protecting the latter. This protective layer 8 prevents cooling of the weld seam and also the access of water to contact the weld seam 10. Moreover the additive 3 when it remains on the hot weld seam 10 burns further on because of the organic substance in it even after the direct influence of the arc, which prevents conti¬ nuousl and effectively the excessively rapid cooling of the weld. In Fig. 4 is shown a welding rod 9 for the adaptation of the invention. In this case a usual, coated or uncoated welding rod 9 is coated with the additive 3 according to the invention. The cavity 7 may naturally also be closed by the additive from the side of the open seam, whereby the arc is in an essentially closed space. In this con¬ nection it is also advisable to take into account an advantageous application of the additive according to the invention, the pastelike additive can namely be applied in advance on the weldable object, in which case welding is performed by a usual welding rod by pushing the welding rod or wire simply through the additive layer and drawing it along the desired weldable joint to produce the weld. The following exemplary performances are intended to illustrate the additive according to the invention. In a preferable application of the invention the paste- like additive consists of the base material, advanta¬ geously mixed with the oily carrier liquid and compris¬ ing: - at least 10 percentages of weight at least one, advan¬ tageously plenty of organic compounds containing biomass, the ashless dry content of which is: - 1...40, preferably 10...13, percentages of weight amino acids, - 0,5...10, preferably 1,5...2,5, percentages of weight fatty acids, - 50...98, preferably 83...87, percentages of weight carbohydrates, preferably carbon compounds with large molecule sizes, and - about 0,5 percentages of weight mineral substances and trace elements. The most suitable biomass materials are the ones, the amino acid composition of which does not contain glyadine or glutenin, which together with water form gluten. When the additive burns because of the arc it forms a protective hard slag layer on the weld.. The additive can also contain several other additives, such as - regulating agent for the pH-value of the additive - lighting agent - hydrogen removal agent - agent enhancing the sufficiency, and - termitic agent or an agent promoting the burning As a regulating agent for the PH-value can be used acid, or inextinguishable, lime or chalk powder and also usual lime, whereby their amount is depending on the desired acidity or alkalinity 10...40 percentages of weight, for underwater use preferably 24 percenta¬ ges, the portion of the usual lime being then about 10 percentages of weight. Moreover it is possible to use in the additive as an extra binding agent a proper commercially generally obtainable glue, e.g. rubber glue. In the performed test concerning the additive according to the invention the welding was made in underwater conditions about 2 m below the water surface, whereby visibility was still relatively good and the lighting agent was not yet necessary. The additive used in the test contained: - 60 percentages of weight base material comprising as an organic substance biomass, the ashless dry con¬ tent of which was:.11,8 percentages of weight amino acids consisting of, as calculated from the total amount of nitrogen with the nitrogen number.6,25, gly- sine.1 ,6%, alanine.1,5%, valine 2,9%, leucine 3,7%, isoleucine 2,1%, serine 3,5%, freonine.1,7%,. cystine 2,0%, metionine 0,7%, phenylalanine 3,2%, tyrosine 0,6%, proline.12,7%, asparatine acid.1,3%, glutamine acid 23,0%, lycine.1 ,1%, arginine 3,9% and histidine 2,5%; 2,1 percentages of weight fatty acids, of which 0,39 percentages of weight oil acid, 1 ,04 percentages lino- leic acid and 0,54 percentages saturated fatty acids; 85,6 percentages of weight carbohydrates, mostly starch containg in small amounts simple sugar compounds and polymers; and 0,5 percentages of weight mineral subs¬ tances and trace elements, - 20 percentages of weight as oily carrier liquid bronze oil, and - 20 percentages of weight a mixture of chalk and lime powders, of which the portion of lime was about.10 per¬ centages of weight. The additive according to the invention was produced by pouring different material components into an about 10 1 vessel and mixing them together as a pastelike ball. Before the welding work was commenced the paste was applied by hand on the weldable seam. The actual welding was performed by drawing the welding rod in the additive layer along the weldable seam. During the welding it was observed that the arc ignited rapidly and that the welding rod moved very lightly .and no splashing or burning-through of the additive layer was observed. . When the formed slag layer was removed from the weld seam after about.1 minute, the seam was still glowing, .the surface of the weld was even and no shape or crack faults could be observed. The welding seam was X-rayed, whereby the class was ob¬ tained as 4 (scale 1...5, of which 5 is the best). In the additive can be included from the welding tech- nics well-known iron or other compounds, such as man- gal, in powder form to enhance for instance the suf¬ ficiency, so that it is possible to compensate splashing and burning losses in this way.. As an addition to the primary carbon containing com¬ pounds included in the biomass it is possible to use for instance iron oxide, the amount of which is in this case 3...8 percentages of weight. Magnesium can be used both as a lighting and hydrogen removal agent, whereby the proper amount is 5...20 per¬ centages of weight of the quantity of the base material. Advantageously as lighting materials can also be used phosphoru , in which case the necessary amount depends on the depth of the welding site and visibility. This amount can even be 20 percentages of weight of the quantity of the base material. Moreover in the additive it is possible to use alumi¬ nium as an agent promoting the burning, whereby its amount can be depending on circumstances even 50 per¬ centages of weight. It must be observed that the invention is not. restricted to the applications described above, but that many modi¬ fications an variations of the additive are possible in the scope of the appended claims. Further it must be noticed that the spreading and guiding equipment of the additive used in the welding can comprise for instance an annular nozzle etc. surrounding the welding rod par¬ tially or totally,or one or more nozzles or the like lo¬ cated in the vicinity of the welding rod or wire. More¬ over the spreading and guiding equipment may comprise a plunger, centrifugal, diaphragm etc. pump or the like, e.g. a screw conveyor. The additive can also be spread simply by hand.

Claims: CLAIMS 1. Pastelike additive used in the underwater arc welding comprising the base material advantageously mixed with the oily carrier liquid and including: - at least.10 percentages of weight at least one base material, preferably plenty of organic compounds comp¬ rising biomass, and possibly - termitic agent - regulating agent for the pH-value of the additive - lighting agent - hydrogen removal agent, and - agent enhancing the sufficiency c h a r a c t e r i z e d in that the ashless dry ma- terial of the biomass in the additive includes: - 1...40, preferably 10...13, percentages of weight amino acids, - 0,5...10, preferably 1,5...2,5, percentages of weight fatty acids, - 50...98, preferably 83«..87, percentages of weight carbohydrates, advantageously carbon compounds with large molecule sizes, and - about 0,5 percentages of weight mineral substances and/or trace elements. 2. Additive according to the claim 1, c h a r a c ¬ t e r i z e d in that it contains: - at least.10 percentages of weight oily carrier liquid, advantageously bronze oil, - 4,5...10 percentages of weight amino acids, - 0,5...2 percentages of weight fatty acids, - 30...80 percentages of weight carbon compounds with large molecular sizes, and - 0,05...0,5 percentages of weight mineral substances and/or trace elements. 3. Additive according to the claim.1 or 2, c h a r a c ¬ t e r i z e d in that it contains iron, mangal etc. compound agents as an additive to enhance the suffi¬ ciency. 4. Additive according to the claim 1 or 2, c h a r a c ¬ t e r i z e d in that it contains as a regulating agent for the pH-value of the additive 10...40, advantageously 20...28, percentages of weight acid lime or chalk powder and common lime, whereby the portion of the common lime is advantageously 8...12 percentages of weight. 5. Additive according to the claim 1 or 2, c h a r a c ¬ t e r i z e d in that it contains as a lighting and hydrogen removal agent magnesium 5...20 percentages of weight of the quantity of the base material. 6. Additive according to the claim 1 or 2, c h a r a c - t e r i z e d in that it contains as a hydrogen removal agent iron oxide 3...8 percentages of weight. 7. Additive according to the claim 1 or 2, c h a r a c - t e r i z e d in that it contains as a termitic agent aluminium powder at the most 50 percentages of weight. 8. Additive according to the claim 1 or 2, c h a r a c ¬ t e r i z e d in that its biomass contains as amino acids calculated from the total amount of nitrogen with the nitrogen number 6,25; glysine 1,1...2,9%, alanine 1,0...2,7%, valine 2,0...5,2%, leucine 2,5...6,7%, iso- leucine.1,4...3,8%, serine 2,4...6,3 %, freonine.1,1... 3,1%, cystine.1 ,4...3,6%, metionine 0,4....1,3%, phenyl- alanine 2,2...5,8%, tyrosine 0,4...1,1%, proline 8,8... 22,9%, asparatine acid 0,9...2,4%, glutamine acid.16,1 ...41,4%, lycine 0,7...2,0%, arginine 2,7...7,1% and histidine.1 ,7...4,5%. 9. Additive according to the claim.1 or 2, c h a r a c ¬ t e r i z e d in that it contains as fatty acids 0,15...0,49 percentages of weight saturated fatty acids, 0,10...0,32 percentages of weight oil acid, 0,28...0,85 percentages of weight linoleic acid and 0,03...0,11 percentages of weight linolenic acid. 10. Additive according to the claim 1 or 2, c h a - r a c t e r i z e d in that the carbon compounds with large molecular sizes are for the major part starch and for the minor part simple sugar compounds and/or sugar polymers.

Inventors: NIINIVAARA JUHANI ENSI KYOESTI, NIINIVAARA, JUHANI, ENSI, KYOESTI
Applicants: NIINIVAARA OY
Application year: 1986
Main classification: B23K35
IPC codes: B23K9, B23K35