JP2008043990A - COPPER PLATED SOLID WIRE FOR Ar-CO2 MIXED GAS SHIELDED ARC WELDING - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a copper plated solid wire for Ar-CO<SB>2</SB>mixed gas shielded arc welding which is excellent in welding workability such as the generation of small amount of sputter, favorable in wire feeding performance, reduced in the wear of a tip, and favorable in arc stability even if welding is performed from a low current region to a transition region for a long period of time. <P>SOLUTION: In the copper plated solid wire for Ar-CO<SB>2</SB>mixed gas shielded arc welding, a wire composition contains 0.02-0.10 mass% C, 0.40-0.95 mass% Si, 1.0-1.95 mass% Mn, 0.03-0.15 mass% Ti, and remaining Fe and inevitable impurities. The surface of the wire has liquid lubricating oil of 0.3-1.5 g per 10 kg of the wire at room temperature, the deposition amount of metal powder is 0.25 g or smaller, and the deposition amount of a solid content other than the metal powder is 0.10 g or smaller. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a copper-plated solid wire for Ar—CO ₂ mixed gas shielded arc welding, and in particular, even when welding for a long time with a welding current from a low current region to a transition region, the spatter generation amount is small and the wire feedability is good. Further, the present invention relates to a copper-plated solid wire for Ar—CO ₂ mixed gas shielded arc welding, which has excellent welding workability, such as less wear of contact tips (hereinafter referred to as tips) and good arc stability.

In the gas shielded arc welding method, all-position welding is possible, and a highly reliable welded joint can be obtained. Therefore, it is widely used in the manufacture of steel structures for transportation equipment such as large structures mainly composed of buildings, bridges, and chemical machinery and automobiles. The shielding gas, due in many cases to use the CO ₂ gas from the economy and defect tolerance, the use of CO ₂ gas amount spatter generation much, cleaning welding point around the surface of the steel sheet (chisel or grinder Sputter removal work) and cleaning work of the shield nozzle at the tip of the welding torch (spatter removal) are required.

Therefore, in particular, when welding is performed using a robot, a mixed gas in which 5 to 25% by volume of CO ₂ gas is mixed with Ar is often used in order to suppress generation of spatter. When this mixed gas is used, the droplet transfer form is sprayed in a high current region, and the amount of spatter generated is extremely small. However, in the low current region, the amount of spatter generated increases as in the case of welding using CO ₂ gas. Also, a relatively large amount of spatter is generated in the welding current in the transition region that is intermediate between the high current region and the low current region.

Therefore, as a technique for suppressing the amount of occurrence of a patch in a low current region, for example, Ar − using a pulse power source in Japanese Patent Application Laid-Open No. 9-99390 (Patent Document 1) and Japanese Patent Application Laid-Open No. 2004-136342 (Patent Document 2). There is a proposal of a wire for CO ₂ mixed gas shielded arc welding.
However, with these technologies, the amount of spatter generated in the welding current from the low current region to the transition region is reduced. However, the pulse power source used is very expensive, and the amount of spatter generated by welding with a general welding power source is small. Wire is needed.

As a technique for suppressing the amount of spatter generated using an Ar—CO ₂ mixed gas, for example, Japanese Patent Application Laid-Open No. 8-132280 (Patent Document 3) and Japanese Patent Application Laid-Open No. 2000-246485 (Patent Document 4) describe a trace amount of Ca. There is a proposal of a welding wire containing K.
However, both of these technologies are intended to reduce spatter when welding is performed in a high current range, that is, when the droplet transition state is in the form of a spray. is not.

Also, when using a robot, welding work is performed by continuously feeding the wire from the conduit tube formed in a spiral shape inside the conduit cable and the tip of the welding torch connected by the feed roller of the wire feeder. However, it is used in a method of arc melting in an atmosphere of Ar—CO ₂ gas. In this case, the conduit cable is long and soft in order to facilitate the movement of the welding torch, and is adjusted up and down or in order to adjust the distance from the wire feeder to the welded part and to weld the narrow part. It is often used by bending left and right or winding it in a loop.

  When used in such a situation, in the above-mentioned welding wire, the lubricant on the surface of the wire by contact friction with the surface in the spiral conduit tube and the copper powder or iron powder adhered to the wire surface during wire production are the conduit tube. It is not satisfactory because the feeding resistance is very large and the arc becomes unstable, the arc becomes unstable, and finally the arc breaks.

On the other hand, recently, various studies have been made on a wire whose surface is not subjected to copper plating. For example, JP-A-11-104883 (Patent Document 5) and JP-A-2004-1061 (Patent Document 6). Discloses a welding wire in which spatter generation is reduced without copper plating. However, there is no accumulation of copper plating on the conduit tube, but if it is welded for a long time at a high current, the tip wear becomes severe and the arc becomes unstable, so it is necessary to change the tip frequently.
JP-A-9-99390 JP 2004-136342 A JP-A-8-132280 JP 2000-246485 A Japanese Patent Laid-Open No. 11-104883 JP 2004-1061 A

The present invention relates to a copper-plated solid wire for Ar—CO ₂ mixed gas shielded arc welding, and in particular, even when welding for a long time with a welding current from a low current region to a transition region, the spatter generation amount is small and the wire feedability is good. Furthermore, an object of the present invention is to provide a copper-plated solid wire for Ar—CO ₂ mixed gas shielded arc welding having excellent welding workability, such as less wear of the tip and good arc stability.

The gist of the present invention is that, in a copper-plated solid wire for Ar—CO ₂ mixed gas shielded arc welding, as wire components, C: 0.02 to 0.10% by mass, Si: 0.40 to 0.95% by mass, Mn : 1.0 to 1.95% by mass, Ti: 0.03 to 0.15% by mass, consisting of the balance Fe and inevitable impurities, and liquid lubricating oil at room temperature per 10 kg of wire on the wire surface 0.3 to 1.5 g, the adhesion amount of the metal powder is 0.25 g or less, and the adhesion amount of solids other than the metal powder is 0.10 g or less. Moreover, it is characterized by further having 0.005-0.25 g of molybdenum disulfide and 0.008-0.10 g of phospholipid on the wire surface.

According to the copper-plated solid wire for Ar—CO ₂ mixed gas shielded arc welding of the present invention, even when welding with a welding current from a low current region to a transition region for a long time, the spatter generation amount is small and the wire feedability is low. This makes it possible to perform welding with excellent welding workability, such as good wear resistance and low arc wear.

In order to solve the above-mentioned problems, the present inventors have used a welding current from a low current region to a transition region (for example, a wire diameter of 1.2 mm, a shielding gas of about 150 to 280 A in the case of Ar-20% CO ₂ ), and a wire Various investigations were made on the components, the feed lubricant applied to the wire surface, and the wire surface condition. As a result, by limiting the content of C, Si, Mn, and Ti in the wire component, the stability of the arc and the occurrence of spatter are suppressed, and the wire surface has copper plating and lubricating oil that is liquid at room temperature, By reducing the amount of solids other than powder and metal powder, the wire feedability is good and the chip wear is extremely reduced and stable even when welding for a long time using a long and soft conduit cable. An arc is obtained. Furthermore, it has been found that by having appropriate amounts of molybdenum disulfide and phospholipid on the surface of the wire, a stable arc can be obtained with good wire feedability.

  C in the wire component is added to suppress the amount of spatter generated. If C is less than 0.02% by mass (hereinafter referred to as “%”), the surface tension is lowered, so that the amount of spatter generated increases. On the other hand, when C exceeds 0.10%, if the surface tension becomes too high, the arc becomes too strong, and large spatter tends to occur.

  Si is added to stabilize the arc. When Si is less than 0.40%, the arc becomes unstable. If it exceeds 0.95%, the surface tension becomes too high and the amount of spatter generated increases. Mn is also added to stabilize the arc as with Si. If Mn is less than 1.0%, the arc becomes unstable. If it exceeds 1.95%, the surface tension becomes too high and the amount of spatter generated increases.

Ti suppresses the generation of spatter by reducing the size of the droplets, particularly with a welding current in a low current range. If Ti is less than 0.03%, the effect is not obtained, and large spatters occur frequently. On the other hand, if Ti exceeds 0.15%, the surface tension becomes too high and the amount of spatter generated increases.
A small amount of Ni, Mo, Cr, Al, Zr, V and Nb can be added to adjust the strength of the weld metal.

  Copper plating on the wire surface reduces the frictional resistance in the conduit tube and improves the electrical conductivity at the tip of the tip to stabilize the arc. Furthermore, even if welding is performed for a long time under high current welding conditions, a stable arc can be sustained with very little tip wear. Copper plating improves the electrical conductivity, lubricity and wear resistance of the chip, and also has the effect of improving rust prevention. The plating thickness is preferably about 0.3 to 1.2 μm.

  Next, the lubricant applied to the wire surface is 0.3 to 1.5 g (hereinafter referred to as g / 10 kgW) of lubricating oil that is liquid at room temperature per 10 kg of wire. Lubricating oil that is liquid at room temperature has a film on the surface of the wire, and improves wire feedability during wire feed. When the lubricating oil is less than 0.3 g / 10 kgW, the feeding resistance increases in the conduit tube, and the wire feeding property becomes poor. On the other hand, if it exceeds 1.5 g / 10 kgW, the wire slips at the feeding roller portion and the arc becomes unstable.

  The lubricating oil 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.

  As described above, copper plating on the wire surface has the effect of improving the electrical conductivity at the tip of the tip, reducing the tip wear, and improving the rust prevention. However, copper plating on the wire surface is performed with the wire diameter (about 2.5 to 3.5 mm) and then reduced to the product diameter by finish drawing, but in this process the copper plating is peeled off and the wire surface A large amount adheres to the surface. At the same time, the iron on the surface of the wire is also scraped off and adheres to the wire surface. When these metal powders adhering to the wire surface are accumulated in the conduit tube and welded for a long time, the feeding resistance becomes very large, the arc becomes unstable, and finally an arc breakage occurs. However, if the adhesion amount of the metal powder on the surface of the wire is 0.25 g / 10 kgW or less, the accumulation amount in the conduit tube is small and the feeding resistance is not increased even if welding is performed for a long time.

  In addition to metal powder such as copper powder and iron powder, residual solid wire lubricant or dirt in the wet wire lubricant adheres to the wire surface and accumulates in the conduit tube and welds for a long time. If so, the feeding resistance increases and the arc becomes unstable. However, if the amount of solids other than metal powder (hereinafter referred to as solid impurities) is 0.10 g / 10 kgW or less, the amount accumulated in the conduit tube decreases, and the conduit tube is worn out and replaced. Does not increase the feeding resistance.

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

  When molybdenum disulfide is welded for a long time by contact with the conduit tube, a small amount of molybdenum disulfide accumulates in the conduit tube. 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.

  Moreover, by having a phospholipid on the wire surface, it has the effect | action which coexists with the lubricating oil which is liquid at normal temperature, and disperse | distributes molybdenum disulfide on the wire surface uniformly. When the phospholipid is less than 0.008 g / 10 kgW, molybdenum disulfide on the wire surface does not adhere uniformly, and there is a portion where the feeding resistance increases in the conduit tube, 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 phospholipid such as lecithin (phosphatidylcon), phosphatidylethanolamine, phosphatidylinitol, about 65% of 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 producing a copper-plated wire for Ar—CO ₂ mixed gas shielded arc welding according to the present invention comprises annealing a wire strand obtained by primary drawing of a wire original wire and plating the surface of the wire, and then finish-drawing to the product diameter. For example, the wire surface is cleaned or mechanically purified, and lubricating oil or lubricating oil and molybdenum disulfide and phospholipid, which are liquid at room temperature, are applied to the surface of the wire to form a spool or pail-packed wire.

Hereinafter, the effect of the present invention will be described in detail with reference to examples.
A spool-wound wire was manufactured by changing the components of the welding wire having a wire diameter of 1.2 mm shown in Table 1, the wire surface condition, and the amount of lubricant applied.

各試作ワイヤにつきワイヤ送給性、チップ摩耗量、アーク状態およびスパッタ発生量を調査した。ワイヤ送給性、チップ摩耗量およびアーク状態の評価は、図１に示す装置を用いて行った。図１において送給機１にセットされたスプール巻きワイヤ２は、送給ローラ３により引き出され、コンジットケーブル４に内包されたコンジットチューブを経てその先端のトーチ５からチップ６まで送給される。そしてチップ６と鋼板７との間でビードオンプレート溶接を行う。コンジットケーブル４は６ｍ長さで、送給抵抗を与えるために１５０ｍｍ径のループを２つ形成した屈曲８を設けた。送給機１には送給ローラの周速度Ｖｒ（設定ワイヤ速度）の検知器（図示せず）およびワイヤの実速度Ｖｗ検出器９を備えている。

The wire feedability, tip wear, arc state, and spatter generation were investigated for each prototype wire. The wire feedability, tip wear amount, and arc state were evaluated using the apparatus shown in FIG. In FIG. 1, the spool winding wire 2 set in the feeder 1 is pulled out by the feeding roller 3 and fed from the torch 5 at the tip thereof to the chip 6 through the conduit tube included in the conduit cable 4. Then, bead-on-plate welding is performed between the tip 6 and the steel plate 7. The conduit cable 4 was 6 m long and provided with a bend 8 formed with two 150 mm diameter loops to give a feeding resistance. The feeder 1 is provided with a detector (not shown) for the peripheral speed Vr (set wire speed) of the feed roller and an actual wire speed Vw detector 9.

  The slip rate SL of the wire feedability evaluation index is represented by SL = (Vr−Vw) / Vr × 100. Further, the reaction force that the wire receives from the conduit tube during wire feeding by the load cell 10 provided in the feeding roller portion was detected as the feeding resistance R. For welding, use a new conduit tube for each prototype wire and check the condition No. shown in Table 2. The welding was performed for 100 minutes under the welding conditions of 1, and the average value was obtained by measuring the slip rate SL and the feeding resistance R for 20 minutes from the start of welding to the end of welding for 40 minutes. When the slip rate SL was 10% or less and the feed resistance R was 6 kgf or less, it was determined that the wire feedability was good. In addition, the wear amount of the tip was measured by using a new tip (inner diameter: 1.4 mm) for each prototype wire and measuring the inner diameter of the portion with the greatest wear after welding. The chip wear amount was evaluated as good when the wear amount was 0.15 mm or less.

スパッタ発生量は、上記ワイヤ送給性およびチップ摩耗性の試験終了後、コンジットチューブおよびチップを交換せずに銅製の捕集箱を用いて、ビードオンプレート溶接により表２に示す条件Ｎｏ．１およびＮｏ．２の溶接条件で５回溶接（１回の溶接時間１．５ｍｉｎ）して捕集したスパッタを１分間の発生量に換算した。スパッタ発生量は０．５ｇ／ｍｉｎ以下でアークが安定して作業性が良好である。また、スパッタ発生量測定後、コンジットチューブのループ部を切断して、潤滑剤、金属粉および固形不純物の蓄積状態を観察した。それらの結果を表３にまとめて示す。

The amount of spatter generated was determined according to the condition Nos. Shown in Table 2 by bead-on-plate welding using a copper collection box without replacing the conduit tube and tip after the wire feedability test and tip wear test were completed. 1 and no. Spatters collected by welding five times under the welding conditions of 2 (one welding time of 1.5 min) were converted to the amount generated for one minute. The amount of spatter generated is 0.5 g / min or less, the arc is stable, and the workability is good. Further, after measuring the amount of spatter generated, the loop portion of the conduit tube was cut, and the accumulation state of the lubricant, metal powder and solid impurities was observed. The results are summarized in Table 3.

表１および表３中、ワイヤＮo.１〜９が本発明例、ワイヤＮo.１０〜１８が比較例である。

In Tables 1 and 3, wires No. 1 to 9 are examples of the present invention, and wires No. 10 to 18 are comparative examples.

  Wire Nos. 1 to 9, which are examples of the present invention, have an appropriate wire component range, have copper plating, an appropriate amount of lubricating oil on the wire surface, and a small amount of metal powder and solid impurities. Low resistance R, good wire feedability, less tip wear, less spatter generation at welding currents from low current region to transition region, stable arc, good welding workability, accumulated amount in conduit tube It was a very satisfactory result such as a small amount.

  Since wire No. 1 had no molybdenum disulfide and phospholipid attached to the surface of the wire, wire No. 2 had no phospholipid attached, so that the wire feeding resistance R was slightly increased. In the comparative example, the wire No. 10 has a large spatter due to the high C of the wire component. Moreover, since the adhesion amount of molybdenum disulfide on the wire surface is small, the feeding resistance R is also increased.

  Wire No. 11 had a large amount of spatter due to the low C of the wire component. Further, since the amount of phospholipid attached to the wire surface was small, the feeding resistance R was also increased. The wire No. 12 had a large amount of spatter due to the high Si of the wire component. Further, since the amount of lubricant attached to the wire surface was large, the arc was unstable and the slip rate SL was also high. The wire No. 13 had an unstable arc because the wire component Si was low. In addition, the amount of sputter generation increased due to the large amount of molybdenum disulfide deposited on the wire surface.

  Wire No. 14 had a large amount of spatter due to its high Mn wire component. In addition, since the amount of lubricant attached to the wire surface is small, the feeding resistance R is also high. The wire No. 15 had an unstable arc because the wire component Mn was low. In addition, the amount of spatter generated increased due to the large amount of phospholipid adhering to the wire surface. The wire No. 16 had a large amount of spatter generated due to the low Ti of the wire component. Further, since the amount of metal powder adhering to the wire surface is large, the amount of accumulation in the conduit tube is large, the feed resistance R is high, and the arc is also unstable.

  The wire No. 17 had a large amount of spatter due to a large amount of Ti as a wire component. Further, since the amount of solid impurities adhering to the wire surface is large, the amount of accumulation in the conduit tube is large, the feed resistance R is high, and the arc is also unstable. Since the wire No. 18 was not plated on the wire surface, the tip wear amount was large and the arc was unstable.

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 Tip 7 Steel plate 8 Bending part of conduit cable 9 Wire actual speed detector 10 Load cell


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

Claims (2)

In the copper-plated solid wire for Ar—CO ₂ mixed gas shielded arc welding, as wire components, C: 0.02 to 0.10 mass%, Si: 0.40 to 0.95 mass%, Mn: 1.0 to 1 .95% by mass, Ti: 0.03 to 0.15% by mass, consisting of the balance Fe and unavoidable impurities, and 0.3-1. A copper-plated wire for Ar—CO ₂ mixed gas shielded arc welding, comprising 5 g, having an adhesion amount of metal powder of 0.25 g or less, and an adhesion amount of solids other than metal powder being 0.10 g or less. 0.005~0.25g molybdenum disulfide on the wire surface, according to claim 1, wherein the Ar-CO ₂ mixed gas shielded arc welding of copper-coated wire, characterized in that it comprises a phospholipid 0.008~0.10g further .

Images