JP2009274127A - Wire for gas-shielded arc welding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wire for the gas-shielded arc welding capable of achieving the excellent wire feedability during the welding for a short period through a long period and performing the welding with consistent arc even when a long liner is used, and many bend parts are present. <P>SOLUTION: A plurality of long grooves which are discontinuous in the longitudinal direction of a wire surface for the gas-shielded arc welding are formed in the circumferential direction of the wire. Molybdenum disulfide is fixed to the long grooves by 0.005-0.20g per 10 kg of the wire, and further, the feeding lubricant consisting of one or more kinds of lubricating oil which is liquid at normal temperature is deposited by 0.5-3.0g per 10 kg of the wire. The feeding lubrication contains 0.005-0.25g molybdenum disulfide and 0.008-0.10g phospholipid per 10 kg of the wire for the gas-shielded arc welding. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a wire for gas shielded arc welding for fully automatic and semi-automatic welding excellent in wire feedability and arc stability.

  Generally, for gas shielded arc welding, a welding wire having a small diameter (0.8 to 1.6 mm) is used. The wire for gas shielded arc welding is used for welding in a form wound on a spool or loaded in a pail pack. When using the wire for gas shielded arc welding, the wire is pulled out from the spool or pail pack by the feeding roller of the feeder and pushed into a conduit liner (hereinafter referred to as a liner) included in a subsequent conduit cable. A system is adopted in which the sheet is fed to the power feed tip in the welding torch attached to the end of the conduit cable via the liner. The wire is subjected to arc welding by applying a voltage between the power supply tip and the material to be welded.

  The liner used here is a flexible guide tube formed by spiraling a steel wire, and its length is usually about 3 to 6 m, but it is 10 to 20 m long when welding over a wide area. It is selected and used according to the distance to the weld. According to this method, there is an advantage that welding can be relatively easily performed along the conduit cable (liner) even in a place where the welding site is narrow or has a height difference.

  However, the following problems may occur at the time of use, and the solution is demanded. In order to perform stable welding, it is necessary that the gas shielded arc welding wire is supplied to the welded portion at a predetermined speed, that is, the wire feedability is good. The wire is pushed into the liner by the feeding force of the feeding roller, while receiving resistance due to contact friction from the inner surface of the liner. At this time, when the liner is used in a relatively gentle use environment close to a straight line, the feeding resistance is not so large, and there is no problem in the wire feeding property, but there are many bent portions, and the bending radius (curvature radius) In a severe use environment such as when the liner is long or the liner is lengthened, the feeding resistance increases, the balance with the feeding force is lost, and the wire feeding performance deteriorates.

  As a method for improving the feedability of the wire for gas shielded arc welding, it is important to apply a lubricant having good slipperiness to the wire surface. As the lubricant, hydrocarbon mineral oil, animal oil and vegetable oil are applied to the wire surface as described in JP-A-7-97583 (Patent Document 1) and JP-A-8-155671 (Patent Document 2). There is a disclosure of a technique that improves the wire feedability by coating. However, with wires coated with these lubricants, a long liner was used and welding with many bent parts had high feeding resistance, poor wire feeding performance, and arc was very unstable. .

JP-A-2004-34131 (Patent Document 3) discloses a base oil composed of one or more selected from the group consisting of vegetable oils, animal oils, mineral oils and synthetic oils to MoS ₂ , WS ₂ , A gas shielded arc welding wire in which a feed lubricant in which a solid lubricant composed mainly of graphite and PTFE or a mixture of at least one kind of main component is uniformly applied in the longitudinal direction and the circumferential direction of the wire is disclosed in JP 2003-225794 A (Patent Document 4) discloses a gas shielded arc welding wire having MoS ₂ , BN, wax, K compound and copper powder in the lower layer portion of the wire surface and fatty acid ester and / or lubricant in the upper layer portion. It is disclosed. Welding wires containing these solid lubricants easily fall off from the wire surface due to contact with the liner, particularly at the liner inlet, and in the case of a long liner, the amount of lubricant adhering to the wire surface near the welding torch is reduced. Increases the feeding resistance. In addition, solid lubricant that has fallen off, copper plating powder scraped by friction with the liner, Fe powder and Zn powder on the surface of the liner scraped by friction with the wire, Fe powder, etc. accumulate in the liner, so long-term welding Then, there is a problem that the wire feedability gradually deteriorates and the arc becomes unstable.

On the other hand, for wires that are not plated with copper on the surface of the wire, various researches have been conducted from the advantages such as the above-mentioned problem of plating peeling and the fact that the process can be omitted at the time of wire production and the handling of plating waste liquid becomes unnecessary. Has been put to practical use. For example, in Japanese Patent Laid-Open No. 11-147195 (Patent Document 5), plating in which a hydrocarbon compound having a ring structure is present on the surface of a wire to prevent peeling of the lubricating material and obtain good wire feedability. None steel wire is disclosed. Further, JP-A-2005-169415 (Patent Document 6) discloses a solid lubricant comprising at least one of higher fatty acids, alkali soaps, metal soaps, MoS ₂ , graphite, BN, fluoride, talc and mica. A non-plated steel wire is disclosed in which one or more liquid lubricants of fatty acid ester and lubricating oil are applied to the coating and its outer periphery, and the spatter generation amount is excellent and the wire feedability is excellent.

  However, unplated steel wires with a lubricant applied to the wire surface are prone to drop off from the wire surface due to contact with the liner, particularly at the inlet side of the liner, and in the case of a long liner, the wire surface near the welding torch This reduces the amount of lubricant adhered and increases the feeding resistance. In addition, lubricant that has fallen off, Fe powder scraped by friction with the liner, and Zn powder and Fe powder scraped by friction with the wire accumulate in the liner. The feedability deteriorates and the arc becomes unstable. Furthermore, the tip is also unsatisfactory due to the problem of the arc becoming unstable and the arc becoming unstable.

The improvement of the wire feedability is strongly demanded for the flux-cored wire with and without plating, which is excellent in welding workability in semi-automatic and all-position welding and capable of highly efficient welding.
JP-A-7-97583 JP-A-8-155671 JP 2004-34131 A JP 2003-225794 A Japanese Patent Laid-Open No. 11-147195 JP 2005-169415 A

  The present invention uses a long liner and performs welding with a stable arc with a good wire feeding property from a short time to a long time welding even when there are a large number of bent parts, and with little tip wear. An object of the present invention is to provide a wire for gas shielded arc welding that can be used.

  The gist of the present invention is that there are a plurality of long grooves discontinuous in the longitudinal direction of the wire surface for gas shielded arc welding, and molybdenum disulfide is 0.005 to 0.20 g per 10 kg of wire in the long grooves. Furthermore, 0.5 to 3.0 g of feed lubricant composed of one or more lubricants that are fixed and liquid at room temperature is adhered per 10 kg of wire. Further, in the gas shielded arc welding wire, the supply lubricant further has 0.005 to 0.25 g of molybdenum disulfide and 0.008 to 0.10 g of phospholipid per 10 kg of the wire.

  According to the gas shielded arc welding wire of the present invention, even when a long liner is used and there are many bent portions, the current supply at the power supply tip is stable, and even when welding is performed for a short time to a long time. Good wire feedability and arc stable welding are possible.

  In order to solve the above-mentioned problems, the present inventors have made various studies on the surface state of the wire for gas shielded arc welding and the supply lubricant to be applied. As a result, molybdenum disulfide is fixed to a long groove having a plurality of long grooves that are discontinuous in the wire surface longitudinal direction, and a supply lubricant made of lubricating oil that is liquid at room temperature is applied to the upper part thereof. The present inventors have found that, regardless of the length and bending of the liner, good wire feedability and arc-stable welding can be achieved even in welding from a short time to a long time. Furthermore, it has also been found that the wire feedability is further improved by having molybdenum disulfide and phospholipid in the feed lubricant together with the lubricating oil which is liquid at room temperature on the wire surface.

Hereinafter, the contents of the present invention will be described in detail.
FIG. 1 shows a schematic view of the surface of a wire for gas shielded arc welding according to the present invention. The wire surface 1 has a plurality of discontinuous long grooves 3 in the longitudinal direction 2 in the wire circumferential direction 4. 2 and 3 schematically show AA sectional views of FIG. Since molybdenum disulfide is fixed in the groove of the long groove 3, the wire surface 1 comes into contact with the conduit liner even if it is welded for a long time using a long liner, and the coating of the feed lubricant 5 is scraped off. However, molybdenum disulfide fixed in the long groove 3 does not lower the frictional resistance and increase the wire feeding resistance. Further, chip wear is extremely reduced even in a wire without plating. In the figure, 6 indicates a plating layer or steel substrate, and 7 indicates molybdenum disulfide as a feed lubricant.

  When the fixed amount of molybdenum disulfide in the long groove is less than 0.0005 g per 10 kg of wire (hereinafter referred to as “g / wa 10 kgW”), when a long liner is used, the frictional resistance increases and sufficient wire feedability is achieved. The improvement effect cannot be obtained. Further, in the case of a wire without plating, the amount of wear of the tip becomes large and the arc becomes unstable. On the other hand, if the molybdenum disulfide adhesion amount in the long groove exceeds 0.20 g / 10 kgW, the wire slips at the wire feed roller portion, making it difficult to feed the wire.

  A feed lubricant consisting of one or more lubricants that are liquid at room temperature on the wire surface forms a lubricating film by physical adsorption with the wire surface to improve wire feedability during wire feeding and rust resistance To improve. The lubricating oil that is liquid at room temperature may be animal or vegetable oil, mineral oil, or synthetic oil. Palm oil, rapeseed oil, castor oil, pig oil, cow oil, fish oil, etc. can be used as animal and vegetable oils, and machine oil, turbine oil, spindle oil, etc. can be used as mineral oils. As the synthetic oil, hydrocarbon type, ester type, polyglycol type, polyphenol type, silicone type and fluorocarbon type can be used.

  The feed lubricant adhesion amount on the wire surface is 0.5 to 3.0 g / 10 kgW. When the amount of the feed lubricant adhering to the wire surface is less than 0.5 g / 10 kgW, the friction coefficient between the wire surface and the liner increases due to insufficient lubrication performance, and the effect of suppressing the increase in feed resistance cannot be expected. It becomes defective. On the other hand, if it exceeds 3.0 g / 10 kgW, the feed roller slips due to excessive adhesion, making it difficult to stably feed the wire. In addition, when the welding is performed for a long time, the feed lubricant is deposited in the liner and the wire feedability becomes poor. Furthermore, since the lubricating oil component is composed of C—H bonds, a large amount of hydrogen is mixed during welding, and pits and blowholes are likely to occur in the weld metal portion.

  Furthermore, by having molybdenum disulfide as the feed lubricant on the wire surface, the feed resistance is suppressed in the liner to further improve the wire feedability. When the feed lubricant molybdenum disulfide is less than 0.005 g / 10 kgW, the feed resistance increases in the liner and the wire feedability becomes poor. Conversely, when molybdenum disulfide exceeds 0.25 g / 10 kgW, the arc becomes unstable and the amount of spatter generated increases.

  It should be noted that a small amount of molybdenum disulfide, which is a feeding lubricant, is accumulated in the liner when it is welded for a long time by contact with the liner, and this accumulated molybdenum disulfide serves to reduce the feeding resistance. Moreover, it is preferable that the particle size of molybdenum disulfide is 1.0 μm or less because the feeding resistance is reduced and the wire feeding property is improved. Further, by having the phospholipid in the supply lubricant on the wire surface, it has an action of uniformly dispersing molybdenum disulfide on the wire surface in coexistence with a lubricating oil that is liquid at room temperature. When the phospholipid is less than 0.008 g / 10 kgW, molybdenum disulfide on the surface of the wire does not adhere uniformly, and there is a portion where the feeding resistance increases in the liner, resulting in poor wire feeding performance. Conversely, when the phospholipid exceeds 0.10 g / 10 kgW, the amount of spatter generated increases.

  The phospholipid referred to in the present invention is a powder containing about 95% of a phospholipid such as lecithin (phosphatidylcon), phosphatidylethanolamine, phosphazinynititol, about 65% phospholipid and There are pastes containing about 35% vegetable oil such as soybean oil, and any of them can be used. Among them, lecithin obtained from soybean oil is preferable.

  The method for manufacturing a wire for gas shielded arc welding according to the present invention comprises: molybdenum disulfide or molybdenum disulfide containing carrier material on the surface of a wire having a wire diameter of 2 to 4 mm with or without copper plating on the wire surface. Adhering and drawing to a product diameter with a roller die or a hole die, a plurality of discontinuous long grooves in the wire surface longitudinal direction are provided in the wire circumferential direction, and molybdenum disulfide is fixed in the long grooves. Next, a supply lubricant is applied to obtain a product. The size of the long groove and the fixed amount of molybdenum disulfide in the long groove are adjusted by changing the wire diameter, the particle diameter of the molybdenum disulfide and the amount of diameter reduction.

  The amount of molybdenum disulfide fixed is measured by washing the surface of the wire with toluene or hexane and then dissolving the copper plating on the surface of the wire with a solution of ammonia water and persulfate aqueous solution. Molybdenum disulfide is analyzed, and the wire without plating is obtained by dissolving the wire surface with an aqueous hydrochloric acid solution and analyzing the molybdenum disulfide in the solution.

  As shown in FIGS. 4A and 4B, the gas shielded arc welding wire of the present invention is a seam type having a cross-sectional structure in which a flux 9 is filled in a steel outer shell 7 and a seam 10 is provided. The target is a flux-cored wire without plating, a seamless-type flux-cored wire having a cross-sectional structure shown in FIG. 4C and a copper-plated flux-cored wire, and a solid wire without plating and copper plating.

Hereinafter, the effect of the present invention will be described in detail with reference to examples.
4 (a) seam type (without plating) and seamless type (with and without plating) flux-cored wire (JIS Z 3313 YFW-C50DR) and solid wire (JIS Z 3312 YGW12) in FIG. ) A copper wire with or without copper plating (3 to 4 mm diameter) and various particles (30 μm or less) of molybdenum disulfide alone or a mixture of molybdenum disulfide and an inorganic compound carrier material are attached to the wire. After drawing and attaching discontinuous long grooves in the longitudinal direction of the wire and fixing molybdenum disulfide, various supply lubricants were applied to form a spool winding wire having a wire diameter of 1.4 mm shown in Table 1 .

表１に示す各試作ワイヤを用いて、ワイヤ送給性および溶接後のライナ内への潤滑剤、他の堆積量を調べた。

Using each prototype wire shown in Table 1, the wire feedability, the lubricant in the liner after welding, and other deposition amounts were examined.

  The wire feedability evaluation test was performed using the apparatus shown in FIG. In FIG. 5, the spool winding wire 12 set in the feeder 11 is pulled out by the feeding roller 13 and fed to the torch 15 at the tip of the spool winding wire 12 through the liner included in the conduit cable 14. Then, bead-on-plate welding is performed between the power feed tip and the steel plate 17. The conduit cable 14 has a length of 6 m, and in order to give a feeding resistance to the wire, the conduit cable at the torch is bent into an S shape. Moreover, the bending part 16 which formed two 150 mm diameter loops was provided. The feeder is provided with a detector for the peripheral speed Vr (= set wire speed) of the feed roller and a detector 18 for the actual speed (Vw) of the wire. The slip ratio SL of the feedability evaluation index is expressed by SL = (Vr−Vw) / Vr × 100%. Further, the reaction force that the wire receives from the liner during feeding by the load cell 19 provided in the feeding roller portion was detected as the feeding resistance R. The welding test was performed under the welding conditions shown in Table 2, and a 5-minute break after 10-minute welding was repeated 10 times for a total of 100 minutes, the feeding resistance R and the slip rate SL every 10 minutes were measured, and the average value was obtained. . When the welding resistance R was 5 kgf or less and the slip ratio SL was 3% or less at each welding time, it was determined that the feeding property was good.

また、溶接後のライナ内の堆積量を調査した。堆積量は、ライナを５０ｃｍ間隔で切断し、温トルエン抽出法により全ての堆積物の重量を測定した。堆積量がライナ長さ１００ｃｍ当たり５０ｍｇ以下を良好と判定した。

In addition, the amount of deposit in the liner after welding was investigated. As for the amount of deposition, the liner was cut at intervals of 50 cm, and the weight of all the deposits was measured by a hot toluene extraction method. A deposition amount of 50 mg or less per 100 cm of liner length was judged good.

  The stability of the arc was evaluated by observing the arc state. The spatter generation state was evaluated as ○ with small and small particles, and x with small or large particles. Further, the wear amount of the tip was measured by using a new commercially available tip (inner diameter 1.5 mm) for each test, and measuring the inner diameter of the portion with the largest wear amount after the welding test. The chip wear amount was evaluated as good when the wear amount was 0.1 mm or less. The results are summarized in Table 3.

表１および表３中、ワイヤＮo.１〜８が本発明例、ワイヤＮo.９〜１６は比較例である。

In Tables 1 and 3, wires No. 1 to 8 are examples of the present invention, and wires No. 9 to 16 are comparative examples.

  The wire Nos. 1 to 8, which are examples of the present invention, are made of a feed lubricant containing an appropriate amount of one or more kinds of lubricating oil that is liquid at room temperature, with an appropriate amount of molybdenum disulfide fixed to discontinuous long grooves in the longitudinal direction of the wire surface. Since an appropriate amount was applied, the feeding resistance R and slip ratio SL were low, the arc was stable, and the amount of deposit in the liner was small, which was a very satisfactory result. Wires No. 2, 4, 6 and No. 7 contain appropriate amounts of molybdenum disulfide and phospholipid (lecithin, phosphatidylethanolamine) in the feed lubricant, so that the feed resistance R is all The wire feedability was very good at less than 3 kg.

  In the comparative example, the wire No. 9 had a high feeding resistance R because the amount of molybdenum disulfide fixed to the discontinuous long grooves in the longitudinal direction of the wire surface was small. Further, the amount of wear of the tip was large and the arc was unstable. Wire No. 10 had a large sum of ester synthetic oil and palm oil as feed lubricants, so the slip ratio SL was high, the arc was unstable, and the amount of deposit in the liner was also large. In addition, the feed resistance R was slightly high because there was little molybdenum disulfide in the feed lubricant.

  Since wire No. 11 had no molybdenum disulfide fixed to discontinuous long grooves in the longitudinal direction of the wire surface, the feed resistance R was high and the arc was somewhat unstable. Further, since the total amount of lecithin and phosphatidylethanolamine was large, the amount of spatter generated was large. Since the wire No. 12 had a large amount of molybdenum disulfide fixed to the discontinuous long grooves in the longitudinal direction of the wire surface, the slip rate SL was high and the arc was unstable. The wire No. 13 had a large amount of palm oil as the feed lubricant, so the slip ratio SL was high, the arc was unstable, and the amount of deposit in the liner was also large.

  Since the wire No. 14 has less rapeseed oil as the feed lubricant, the feed resistance R was increased. In addition, since the supply lubricant was a large amount of molybdenum disulfide, the arc was unstable and the amount of spatter was large. Since the wire No. 15 had less ester synthetic oil as the feed lubricant, the feed resistance R was high and the arc was somewhat unstable. Since the wire No. 16 has a large amount of palm oil as the feed lubricant, the slip rate SL is high, the arc is unstable, and the amount of deposit in the liner is also large. Moreover, since there was little lecithin, feeding resistance R was a little high.

It is a schematic diagram of the wire surface for gas shielded arc welding of this invention. It is AA sectional drawing of FIG. It is AA sectional drawing of FIG. It is the schematic diagram which showed the cross-sectional structure example of the flux cored wire. It is drawing which shows the apparatus of the wire feeding test in the Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Wire surface 2 Wire longitudinal direction 3 Long groove 4 Wire circumferential direction 5 Feed lubricant 6 Plating layer or steel base 7 Molybdenum disulfide of feed lubricant 8 Steel outer skin 9 Flux 10 Joint 11 Feeder 12 Spool winding Wire 13 Feed roller 14 Conduit cable 15 Torch 16 Conduit cable bent portion 17 Steel plate 18 Wire actual speed detector 19 Load cell


Patent Applicant Nippon Steel & Sumikin Welding Co., Ltd.
Attorney Attorney Shiina and others 1

Claims (2)

A plurality of long grooves discontinuous in the longitudinal direction of the wire surface for gas shielded arc welding are provided in the circumferential direction of the wire, and 0.005 to 0.20 g of molybdenum disulfide is fixed to the long grooves per 10 kg of the wire. A gas shielded arc welding wire, characterized in that 0.5 to 3.0 g of a feed lubricant consisting of one or more kinds of lubricating oil is attached per 10 kg of the wire. The wire for gas shielded arc welding according to claim 1, further comprising 0.005 to 0.25 g of molybdenum disulfide and 0.008 to 0.10 g of phospholipid per 10 kg of the wire in the feed lubricant.

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