JP5238273B2 - Steel wire for gas shielded arc welding - Google Patents

Description

  The present invention relates to a steel wire for gas shielded arc welding such as a flux-cored wire and a solid wire for full-automatic and semi-automatic welding excellent in wire feedability.

  Generally, for gas shielded arc welding, a welding wire having a small diameter (0.8 to 1.6 mm) is used. The steel 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 this steel 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 the conduit liner contained in the subsequent conduit cable. Thus, a method of feeding to a power feed tip in a welding torch attached to the end of the conduit cable is adopted. The wire is subjected to arc welding by applying a voltage between the power supply tip and the material to be welded.

  The conduit 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 even in a place where a welding site such as a shipbuilding 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 steel wire for gas shielded arc welding is supplied to the welded portion at a fixed speed, that is, the wire feedability is good. The wire is pushed into the conduit liner by the feeding force of the feeding roller, while receiving the feeding resistance due to contact friction from the inner surface of the conduit liner. In this case, when the conduit liner is 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) ) Is small, or in a severe usage environment such as when the conduit 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 steel 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 conduit liner is used, and welding with a large number of bent parts has high feed resistance, poor wire feedability, and the arc is very unstable. It was.

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 steel wire for gas shield arc welding 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 and circumferential directions of the wire is disclosed No. 225794 (Patent Document 4) discloses a steel for gas shielded arc welding 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. A wire is disclosed.

Welding wires containing these solid lubricants can easily fall off the wire surface due to contact with the conduit liner, especially on the inlet side of the conduit liner. In the case of a long conduit liner, the amount of lubricant adhering to the wire surface near the welding torch Decreases and the feeding resistance increases. In addition, solid lubricant that has fallen off, copper plating powder scraped by friction with the conduit liner, Fe powder and Zn powder on the surface of the conduit liner scraped by friction with the wire, Fe powder, etc. accumulate in the conduit liner, When welding for a long period of time, there is a problem that the wire feedability gradually deteriorates and the arc becomes unstable.
JP-A-7-97583 JP-A-8-155671 JP 2004-34131 A JP 2003-225794 A

  The present invention is a gas shield that uses a long conduit liner and can perform welding with good wire feedability and stable arc from short time to long time welding even when there are many bent portions. It aims at providing the steel wire for arc welding.

The gist of the present invention is that the surface of the steel wire for gas shielded arc welding is 8 to 30% by mass of molybdenum disulfide in one or more base oils of lubricating oil that is liquid at room temperature, 1 of an oil-soluble polymer compound. 5 to 15% by mass of seeds or more, 1 to 10% by mass of one or more types of phospholipids, and 0.5 to 3.0 g of a feed lubricant consisting of other inevitable impurities is attached per 10 kg of wire. The steel wire for gas shielded arc welding is a feature.

  The steel wire for gas shielded arc welding according to the present invention uses a long conduit liner and has good wire feedability and arc for welding in a short time to a long time even in a case where there are many bent portions. However, stable welding is possible.

  In order to solve the above-mentioned problems, the present inventors have made various studies on a feed lubricant applied to the surface of a steel wire for gas shielded arc welding. As a result, by applying a feed lubricant containing appropriate amounts of molybdenum disulfide and an oil-soluble polymer compound to the base oil of the lubricating oil that is liquid at room temperature on the wire surface, it is related to the length and bending of the conduit liner. In addition, it has been found that 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 a better wire feeding property can be exhibited by including a phospholipid in the feeding lubricant.

Hereinafter, the contents of the present invention will be described in detail.
Molybdenum disulfide has a very low frictional resistance with the conduit liner and improves the wire feedability. Molybdenum disulfide that is gradually dropped by contact with the conduit liner is deposited in the conduit liner by welding for a long time, but the deposited molybdenum disulfide further reduces the frictional resistance between the conduit liner and the wire. Therefore, even when welding for a long time, the wire feedability is good and stable welding is possible. When the molybdenum disulfide in the feed lubricant is less than 8% by mass, the wire feedability becomes poor particularly when welding for a long time. On the other hand, when molybdenum disulfide exceeds 30% by mass, the wire slips at the wire feed roller portion, making it difficult to feed the wire. In addition, it is preferable that the particle diameter of molybdenum disulfide is 1.0 μm or less because the feeding resistance is reduced and the wire feeding property is improved.

  One or more of the oil-soluble polymer compounds have an action of uniformly dispersing the molybdenum disulfide on the wire surface and firmly attaching the molybdenum disulfide to the wire surface, thereby preventing the molybdenum disulfide from falling into the conduit liner. Examples of the oil-soluble polymer compound include polymer compounds having an average molecular weight of 600 to 500,000 such as polybutene, polyisobutylene, polyacrylic acid ester, polymethacrylate, polyacrylic acid, maleated polybutene, polyethylene, and polypropylene.

  If one or more of the oil-soluble polymer compounds is less than 5% by mass, molybdenum disulfide cannot be uniformly dispersed, and the wire feed resistance partially increases or the wire slips at the feed roller portion. Further, in long-time welding, the feed lubricant is deposited in the conduit liner, and the wire feedability becomes poor. On the other hand, if one or more of the oil-soluble polymer compounds exceeds 15% by mass, the electrical conductivity at the tip portion becomes poor and the arc becomes unstable.

  The feed lubricant adhesion amount on the wire surface is 0.5 to 3.0 g (hereinafter referred to as g / 10 kgW) per 10 kg of the wire. If the adhesion amount of the feed lubricant on the wire surface is less than 0.5 g / 10 kgW, the friction coefficient between the wire surface and the conduit liner increases due to insufficient lubrication performance, and the effect of suppressing the increase in feed resistance cannot be expected. Becomes defective. On the other hand, if it exceeds 3.0 g / 10 kgW, the wire slips at the feed roller portion 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 conduit liner, resulting in poor wire feedability. 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, the phospholipid uniformly disperses molybdenum disulfide and the oil-soluble polymer compound in the base oil and uniformly coats the wire surface, and improves the conductivity of the lubricant. When one or more phospholipids are less than 1% by mass, molybdenum disulfide and the oil-soluble polymer compound are easily segregated on the wire surface, and a portion where the wire feeding property is not stable is generated. On the other hand, if it exceeds 10% by mass, the amount of spatter generated increases and welding workability deteriorates.

  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 base oil of the lubricating oil that is liquid at room temperature used in the present invention forms a lubricating film by physical adsorption with the wire surface to improve wire feedability during wire feeding and improve rust resistance. 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 steel wire for gas shielded arc welding that is the subject of the present invention can be applied to any of solid wire, seamless type and seam type flux-cored wire, and can also be applied to these plated wires and non-plated wires.

Hereinafter, the effect of the present invention will be described in detail with reference to examples.
Various feed lubricants were applied to a flux-cored wire (JIS Z 3313 YFW-C50DR) and a solid wire (JIS Z 3312 YGW11) having a product diameter of 1.4 mm shown in Table 1 to form a spool-wound wire. In addition, the adhesion amount of the supply lubricant of each trial wire was measured by a hot toluene extraction method.

各試作ワイヤを用いてワイヤ送給性および溶接後のコンジットライナ内への潤滑剤、他の堆積量を調べた。

Using each prototype wire, the wire feedability, the lubricant in the conduit liner after welding, and other deposits were investigated.

  The wire feedability evaluation test was performed using the apparatus shown in FIG. In FIG. 1, the spool winding wire 2 set in the feeder 1 is pulled out by a feeding roller 3 and fed to a torch 5 at the tip of the spool winding wire 2 through a conduit liner included in a conduit cable 4. Then, bead-on-plate welding is performed between the power feed tip and the steel plate 7. The conduit cable 4 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 6 which formed two 150 mm diameter loops was provided. The feeder 1 is provided with a detector for the peripheral speed Vr (= setting wire speed) of the feeding roller 3 and an actual wire speed (Vw) detector 8. The slip ratio SL of the feedability evaluation index is expressed by SL = (Vr−Vw) / Vr × 100%. Further, the reaction force received by the wire from the conduit liner during feeding by the load cell 9 provided in the feeding roller portion was detected as the feeding resistance R.

  In the short-time feedability test, welding resistance was measured for 2 minutes under the welding conditions shown in Table 2, the feed resistance R and the slip ratio SL were measured, and the average value was obtained. When the feeding resistance R was 5 kgf or less and the slip ratio SL was 2% or less, it was determined that the feeding property was good. Further, the maximum values of the instantaneous feeding resistance R and slip ratio SL due to the energization failure were measured, and the feeding resistance R: 6 kgf or less and the slip ratio SL: 3% or less were determined to be satisfactory.

長時間溶接試験は、表２に示す溶接条件で図１に示すコンジットケーブルの手元Ｓ字屈曲と１５０ｍｍ径のループ１つの屈曲条件として、１０分溶接後５分休憩を１０回繰り返し合計１００分溶接し、１０分毎の送給抵抗Ｒとスリップ率ＳＬを測定し、平均値を求めた。各溶接時間で送給抵抗Ｒが５ｋｇｆ以下、スリップ率ＳＬが３％以下の場合に送給性良好と判定した。スパッタ発生状況は目視で行った。

In the long-term welding test, the welding conditions shown in Table 2 were used, and the conduit cable shown in FIG. Then, the feeding resistance R and the slip ratio 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. Sputtering was visually observed.

  In addition, the amount of deposit in the conduit liner after 100 minutes of welding was investigated. As for the amount of deposition, the conduit liner was cut at intervals of 50 cm, and the weight of all deposits was measured by a hot toluene extraction method. The amount deposited was determined to be 50 mg or less per 100 cm length of the conduit liner. The results are summarized in Table 3.

表１および表３中、ワイヤＮo.１〜５が本発明例、ワイヤＮo.６〜１１は比較例である。

In Tables 1 and 3, wires No. 1 to 5 are examples of the present invention, and wires No. 6 to 11 are comparative examples.

Wire Nos. 1 to 5, which are examples of the present invention, are feed lubrication containing an appropriate amount of molybdenum disulfide and an oil-soluble polymer compound in the base oil of the lubricating oil that is liquid at room temperature on the wire surface, and further including an appropriate amount of phospholipid. Since a proper amount of the agent was applied, both the short-time welding test and the long-time welding test had extremely satisfactory results such as low feed resistance R and slip ratio SL, stable arc, and a small amount of deposit in the conduit liner. .

Since the wire No. 6 in the comparative example contained a large amount of molybdenum disulfide in the feed lubricant, the slip ratio SL was high and the arc was unstable in both the short-time welding test and the long-time welding test. Since wire No. 7 contained less molybdenum disulfide in the feed lubricant, the feed resistance R was high and the arc was unstable in the long-time welding test. Moreover, since there were many phospholipids (lecithin), the amount of spatter generation also increased.

Wire No. 8 had a large total amount of oil-soluble polymer compounds (polybutene and polyisobutene) in the feed lubricant, so that the electrical conductivity at the tip portion was poor and the arc became unstable. In addition, since no phospholipid was contained, the feed resistance R was slightly increased in both the short-time welding test and the long-time welding test. Since wire No. 9 has a small amount of oil-soluble polymer compound (polyisobutene) in the feed lubricant, the arc becomes somewhat unstable in the short-time welding test and the feed resistance R and slip ratio SL are low. The highest price has increased. In the long-time welding test, the wire feed resistance R was high, the arc was unstable, and the amount of deposit in the conduit liner was large.

Since wire No. 10 has a large amount of feed lubricant adhering to the wire surface, the slip rate SL was high and the arc was unstable in both the short-time welding test and the long-time welding test. Further, in the long-time welding test, the feeding resistance R was high, and the amount of deposit in the conduit liner was large. Since the wire No. 11 had a small amount of feeding lubricant adhering to the wire surface, the feeding resistance R was high and the arc was unstable in both the short-time welding test and the long-time welding test.

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 Feeder 2 Spool winding wire 3 Feed roller 4 Conduit cable 5 Torch 6 Conduit cable bending part 7 Steel plate 8 Wire actual speed detector 9 Load cell


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

Claims (1)

8 to 30% by mass of molybdenum disulfide and 1 to 15% by mass of one or more oil-soluble polymer compounds in one or more base oils of a lubricant that is liquid at room temperature on the surface of the steel wire for gas shielded arc welding , A steel for gas shielded arc welding characterized by containing 0.5 to 3.0 g of a feed lubricant containing 1 to 10% by mass of one or more phospholipids and other inevitable impurities per 10 kg of wire. Wire.

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