JP2006315059A - Copper-plated solid wire for arc welding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a copper-plated solid wire in which, by controlling the form of its surface, a sliding contact point to be formed between a feed tip and the wire surface upon welding is stably melted, and sudden solidification at the sliding contact point does not occur upon continuous welding, and which has excellent wire feeding property and arc stability, and has satisfactory welding operability with reduced spatters and fumes. <P>SOLUTION: The surface of the wire is subjected to copper plating in a plating quantity of 0.05 to 0.40 mass%, and, in the cross-section vertical to the longitudinal direction of the wire, recesses 1 opening on the surface of the wire are formed. The number of the recesses 1 is 40 to 400 pieces in the optional cross-section of the wire, and, one or more kinds of oils selected from a vegetable oil, an animal oil, a synthetic oil and a mineral oil in an amount of 0.1 to 2 g per 10 kg wire are present at the surface of the wire and the opening parts of the recesses. Each copper plating layer 2 is present in a state of being folded at the inside of each recess 1. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a solid wire for arc welding that is widely used for welding steel frames, bridges, shipbuilding, automobiles, and the like, and in particular, the feeding resistance inside the conduit liner and the inside of the power feed tip is small, the arc is stable, and the sputtering is performed. Further, the present invention relates to a solid wire for arc welding with copper plating that generates less fume.

As a method for improving the feedability of the solid wire for arc welding, it is common to apply a slippery lubricant to the surface of the wire. Conventionally, as described in Patent Document 1 and Patent Document 2, MoS ₂ , WS ₂ , PTFE, C, fluorinated graphite, or metal soap has been proposed as a lubricant applied to the wire surface. All of these lubricants are applied to improve the feedability of the wire and stabilize the feed.

  Furthermore, Patent Literature 3, Patent Literature 4, and Patent Literature 5 disclose a technique for improving the wire feedability by controlling surface irregularities. Patent Document 6 discloses a technique for improving feedability, feedability, and arc stability using free carbon or molybdenum disulfide.

JP-A-6-285678 Japanese Patent Laid-Open No. 9-070684 JP-A-8-001370 Japanese Patent Laid-Open No. 9-070685 Japanese Patent Application No. 2000-117483 JP 2000-14080 A

  However, in the prior art described in each of the above-mentioned publications, it does not stabilize the sliding contact between the wire feed tip having the copper plating on the wire surface and the wire surface. Solid wire does not necessarily have sufficient wire feedability and arc stability, and does not have good welding workability with less spatter and fume.

  The present invention has been made in view of such problems, and by controlling the form of the surface of the copper-plated wire, the sliding contact formed between the power supply tip and the wire surface during welding can be stably provided. Copper plating that melts and does not suddenly solidify at sliding contacts during continuous welding, has excellent wire feedability and arc stability, and has good welding workability with low spatter and fume An object of the present invention is to provide a solid wire with a wire. Further, according to the present invention, when a solid lubricant is used as an auxiliary, the solid lubricant can be held without detaching on the surface of the wire and / or immediately below the surface, and stable wire feedability and arc An object of the present invention is to provide a copper wire with copper plating which has both stability and good welding workability with less spatter and fume.

  The solid wire for arc welding with copper plating according to the present invention is a solid wire for arc welding with copper plating in which a plating amount of 0.05 to 0.40 mass% is plated on the wire surface. In the cross section perpendicular to the wire surface, the number of these pits is 40 to 400 in the arbitrary cross section of the wire, and the amount of 0.1 to 2 g of vegetable oil, animal oil, synthetic oil per 10 kg of wire And one or more oils selected from the group consisting of mineral oils are present on the wire surface and the opening of the recess.

In this solid wire for arc welding with copper plating, the copper plating layer usually exists in a state of being folded in the recess. The number of the depressions is preferably 100 to 400. Further, 0.05 to 0.8 g of one or more powders selected from the group consisting of MoS ₂ , WS ₂ , and ZnS ₂ may be present on the wire surface per 10 kg of the wire. preferable. Furthermore, 0.01 to 0.2 g of one or more powders selected from the group consisting of MoS ₂ , WS ₂ , and ZnS ₂ may exist in the inside of the depression per 10 kg of wire. preferable. In addition, 0.05 to 0.8 g of one or more powders selected from the group consisting of MoS ₂ , WS ₂ , and ZnS ₂ are present on the wire surface per 10 kg of the wire, and at the same time, the depression One or two or more kinds of powders selected from the group consisting of MoS ₂ , WS ₂ and ZnS ₂ may be present within 0.01 to 0.2 g per 10 kg of wire. .

  Alternatively, K compound or Na compound is present in 0.01 or 10.0 mass ppm in terms of K amount or Na amount, respectively, in one or a plurality of portions of the wire surface, the inside of the depression, and the steel ground surface, or The K compound and the Na compound are preferably present in a total amount of 0.01 to 10.0 mass ppm when converted into the K amount and the Na amount, respectively. The K compound and / or Na compound is preferably present alone or in a total amount of 0.1 to 5 ppm by mass in terms of K amount and Na amount.

  The solid wire of the present invention preferably has a center line average surface roughness Ra measured in the circumferential direction of the wire surface of 0.05 to 1.0 μm.

  Further, the composition of the wire is, for example, C: 0.01 to 0.12% by mass, Si: 0.2 to 1.2% by mass, Mn: 0.5 to 2.5% by mass, P: 0.00. It contains 001 to 0.03% by mass and S: 0.001 to 0.03% by mass, with the balance being Fe and inevitable impurities. In this case, Ti + Zr: 0.03 to 0.3% by mass can be further contained, and Mo: 0.01 to 0.6% by mass can be further contained.

  According to the present invention, by controlling the form of the copper-plated wire surface, the sliding contact formed between the power supply tip and the wire surface during welding can be stably melted, and during continuous welding, There is no sudden solidification at the sliding contact. For this reason, wire feedability and arc stability are excellent, and good welding workability with less spatter and fume can be obtained. In addition, when a solid lubricant is used as an auxiliary agent, the solid lubricant can be held on the surface of the wire and / or directly below the surface without being separated, and stable wire feedability and arc stability can be achieved. Good welding workability with little spatter and fume can be obtained.

  Hereinafter, embodiments of the present invention will be specifically described with reference to the accompanying drawings. FIG. 1 is a view showing the shape of a depression existing on the wire surface in a cross section perpendicular to the longitudinal direction of the welding wire. This FIG. 1 traces the boundary of the surface of a solid wire and a copper plating layer in the micrograph of the macro structure of the wire cross section in the solid wire of this invention shown in FIG. 2 (a). FIG. 2B is a macro structure photograph of a wire cross section of a conventional solid wire.

  As shown in FIG. 1, a depression 1 is formed on the surface of the solid wire steel, and a copper plating layer 2 exists inside the depression. At the same time, the copper plating layer 2 is folded in the depression 1, and inside the depression 1. The surfaces of the copper plating layer 2 before being subjected to the wire drawing process are opposed to each other. The structure is greatly different from a structure in which a depression is formed on the surface of the steel and copper plating of different thicknesses is simply filled in the depression. Moreover, this hollow 1 exists continuously in the wire longitudinal direction.

  As described above, the depression 1 exists on the wire surface, and the copper plating layer 2 on the wire surface has a shape folded in the depression 1, so that the slide formed between the power feed tip and the wire surface is formed. The moving contact can be stabilized, the generation amount of spatter and fume can be reduced, and the operation rate of the automatic welding apparatus using a robot or the like can be improved to a very high level.

  In particular, in the case of a solid wire having copper plating, the power feeding tip and the welding wire are repeatedly melted and solidified locally not only at the start and end of welding but also during welding. There is a potential problem of being unable to do so. This is because when the copper plating is applied to the wire surface, the melting and solidification are repeated at the sliding contact formed between the power supply tip and the wire surface. It is assumed that this is because the copper of the power feeding chip is easily fixed. If this instantaneous and local sticking occurs during continuous welding, the wire feed rate fluctuates, the Joule heat generation at the wire protrusion becomes unstable, the droplet transfer phenomenon becomes unstable, and an instantaneous short circuit occurs. appear. This increases the amount of spatter and fume generation.

  Also, if a solid lubricant is applied without any depression on the wire surface, it will be easily detached inside the feed roller or conduit liner, and if the solid lubricant is detached inside the feed roller or conduit liner, the wire feed The effect of improving the property or the effect of reducing the amount of spatter generation decreases. Furthermore, the solid lubricant released by the feed roller reduces the gripping force for feeding the wire, and the solid lubricant released inside the conduit liner accumulates inside the conduit liner, causing clogging and stable. Obstructs wire feeding. As a result, a problem different from the reduction in spatter and fume generation occurs.

  On the other hand, in the present invention, as described above, the depression 1 is formed on the surface of the solid wire steel, and the surfaces of the depressions 1 face each other with the copper plating layer 2 folded inside the depression 1. Therefore, the above problem does not occur.

  The presence of the copper plating layer 2 in a folded form in the depression 1 on the surface of the steel is never stable when the hole die is drawn with a normal wet lubricant and the oil skin is passed in the final process. Can not be formed. The presence form of this copper plating layer 2 is a very special surface form. The recess 1 is formed, for example, by forming irregularities in advance on the surface of the steel element wire by shot blasting or the like at the original wire stage, and plating in the subsequent process to produce a shape in which the plated surface is folded inside. Can do.

  Then, a depression 1 is formed on the surface of the steel ground, copper plating is present inside the depression 1, and the copper plating layer 2 is folded at the same time. Such a depression 1 is continuously formed in the wire longitudinal direction. Such a form can be formed only by using a powder lubricant containing Na soap or K soap as a main component and performing cold drawing of a rolling method such as a micromill or a roller die. Various numbers of rolling rolls such as 2-sided, 3-sided, and 4-sided rolls can be used. The roller die rolling method is a publicly known method disclosed in JP-A-2005-095972, and the micromill rolling method is disclosed in JP-A-08-099116. However, in the method of the present invention, those methods are disclosed. The difference is that there is a contrivance to form the depression 1 in advance before passing through the rolling process and create a state in which the copper plating layer 2 is folded.

  In the final step, a hole die may be used to adjust the wire diameter, but the area reduction is preferably less than 20%. Also, the lubricant used in the hole die should be a powder lubricant mainly composed of Na soap or K soap having excellent lubricity. By using a powder lubricant, good lubricity can be maintained, and even if a recess formed by roll rolling passes through a hole die, it is effectively preserved.

  It is desirable to adjust the softening point by adding an alkali metal nitrite, phosphate, or the like to a powder lubricant containing Na soap or K soap as a main component, if necessary. By using a powder lubricant having a high softening point, the depression 1 can be more effectively generated and left.

Furthermore, if necessary, a maximum of 20% by mass of MoS ₂ , WS ₂ , ZnS is added to a powder lubricant containing Na soap or K soap as a main component, and the wire surface and the inside of the dent are drawn. In addition, MoS ₂ , WS ₂ , and ZnS can remain in a small amount and uniformly.

After washing, an appropriate amount of one or more oils selected from the group consisting of vegetable oil, animal oil, synthetic oil and mineral oil is applied to the wire surface. Furthermore, by adding up to 20% by mass of MoS ₂ , WS ₂ , ZnS to this coating oil and uniformly coating the wire surface, the amount of MoS ₂ , WS ₂ , ZnS present on the wire surface can be freely set. Can be controlled.

Further, the K amount of the wire can be adjusted to an appropriate amount by dissolving or dispersing a K source such as potassium borate, potassium octylate, and potassium naphthenate in the coating oil and applying it to the surface of the wire. Additionally, primitive diameter or prior to annealing at intermediate diameter, K compounds such _{K 2 CO 3, Na 2 CO} 3 on the surface of the wire, by applying an aqueous solution of Na compound, as a seed layer for copper plating steel An internal diffusion layer of K and Na atoms can be formed on the surface, and the amount of K and Na as the whole wire can be adjusted to an appropriate amount.

  The number of the depressions 1 is the number of the perimeter of the wire in the cross section of the wire. The number of the depressions 1 is 40 to 400. When the number of the depressions 1 is less than 40, the sliding contact does not melt stably during welding, and stable power feeding cannot be performed. When the number of the depressions 1 exceeds 400, the adhesion between the steel ground and the copper plating layer is deteriorated, the copper plating layer is easily peeled off, and clogging is caused. However, the number of depressions 1 is preferably 100 or more. Thereby, even at a relatively low welding current of 200 A or less, the sliding contact is stably melted, the power feeding stability is further increased, and the generation amount of fumes is reduced.

  The amount of copper plating on the wire surface is 0.05 to 0.40 mass%. If the copper plating amount is less than 0.05% by mass, the copper plating layer cannot be uniformly covered over the entire length and the entire circumference of the wire surface. Moreover, when the amount of copper plating exceeds 0.40 mass%, the solidification cracking sensitivity of a weld metal will become high.

  One or more oils selected from the group consisting of vegetable oil, animal oil, synthetic oil and mineral oil in an amount of 0.1 to 2 g per 10 kg of wire are present in the wire surface and in the opening of the recess 1. When these oils are less than 0.1 g per 10 kg of wire, a problem occurs in the mechanical slipperiness in the conduit liner, and when it exceeds 2 g, the oil falls off in the conduit liner, and the weld metal There is a problem that the amount of diffusible hydrogen increases.

The total amount of one or more solid powders of MoS ₂ , WS ₂ , ZnS present on the wire surface is 0.05 to 0.8 g per 10 kg of the wire. If the amount of the solid powder existing on the wire surface is less than 0.05 g, mechanical slip occurs in the conduit liner, and if it exceeds 0.8 g, the solid powder falls into the conduit liner. .

In addition, the amount of one or more solid powders of MoS ₂ , WS ₂ , and ZnS present in the hollow 1 on the surface of the wire is 0.01 to 0.2 g per 10 kg of the wire in total. . If the amount of the solid powder existing on the wire surface is less than 0.01 g, the effect of stabilizing the sliding contact cannot be obtained. On the other hand, if it exceeds 0.2 g, the solid powder cannot be held inside the dent, causing clogging.

  In addition, when solid powder exists in both the wire surface and the hollow 1 inside, the amount of these solid powders must satisfy the above-mentioned conditions individually. If the amount of the solid powder is too small for each of the wire surface and the inside of the recess 1, the mechanical slip in the conduit liner and the stabilization of the sliding contact cannot be obtained. Any of these will cause clogging.

  It is preferable that K compound or Na compound exists in the inside of a wire surface and / or a hollow, and 0.01 thru | or 10.0 mass ppm exists in conversion of K amount or Na amount, respectively. When both the K compound and the Na compound are present, it is preferable that the total amount is 0.01 to 10.0 mass ppm when converted into the K amount and the Na amount, respectively. Preferably, the K compound and / or Na compound is present alone or in a total amount of 0.1 to 5 ppm by mass in terms of K amount and Na amount. When these compounds are less than 0.01 mass ppm in terms of K or Na, the effects of arc stabilization and discharge stabilization cannot be obtained. When these compounds exceed 10.0 mass ppm, although there is an arc stabilizing effect, the K compound and / or Na compound is easily peeled off from the wire surface, which causes clogging.

  Moreover, it is preferable that the center line average surface roughness Ra measured in the circumferential direction of the wire surface is 0.05 to 1.0 μm. When Ra is less than 0.05 μm, the oil, powder and compound on the surface of the wire are easily peeled off from the surface, and the substances attached to the surface peel off and cause clogging in the conduit liner. When Ra exceeds 1.0 μm, the adhesion between the steel base and the copper plating layer is deteriorated, the plating layer is easily peeled off, and similarly causes clogging in the conduit liner.

  The composition of the wire is, for example, C: 0.01 to 0.12 mass%, Si: 0.2 to 1.2 mass%, Mn: 0.5 to 2.5 mass%, P: 0.001 to It contains 0.03% by mass and S: 0.001 to 0.03% by mass, with the balance being Fe and inevitable impurities.

  In this case, the composition of the wire preferably further contains Ti + Zr: 0.03 to 0.3% by mass, and further the composition of the wire is Mo: 0.01 to 0.6% by mass. Can be contained. These chemical composition ranges are determined from the mechanical properties of the weld metal, for example, tensile strength, hardness, toughness, elongation, as well as droplet detachability during arc welding, molten pool shape, bead shape, etc. .

  Next, examples of the present invention will be described in comparison with comparative examples that are out of the scope of the present invention, and effects of the present invention will be described. A solid wire having a chemical composition of YGW11 standardized by JIS was prototyped. The chemical compositions of these YGW11 are shown in Table 1 below.

  The YGW-11 wire was reduced in diameter by hot rolling until the diameter became 5.5 mm, and after pickling, a predetermined amount of copper plating layer was formed by electroplating. After plating, a powder lubricant mainly composed of Na soap was used, the diameter was reduced to 1.25 mm by roll rolling, and the diameter was reduced to 1.19 mm using a hole die. After washing, fats and oils, powder and K compound were uniformly applied to the wire surface.

The wire performance was evaluated by the amount of fumes generated during welding. Welding conditions with YGW-11 wire were bead-on-plate welding under the conditions of shielding gas 100% CO ₂ , current 300A, voltage 36V, protrusion length 23mm ± 2mm, welding speed 30cm / min. is there. The steel plate to be welded is JIS SM490A (thickness 12 mm), and the welding power source is a thyristor power source. The evaluation results of welding with YGW-11 wire are shown in Table 2 below.

  As shown in Table 2, in the case of Examples 5 to 19 of the present invention, the amount of generated fume was reduced as compared with the cases of Comparative Examples 1 to 4 that are out of the scope of the present invention. In particular, in Examples 8 to 19 in which the number of depressions was 100 or more, the amount of fume generation was further reduced.

  Next, an embodiment in which a welding wire of JIS standard YGW18 is used will be described. A welding wire of YGW18 having a chemical composition shown in Table 3 below was made as an experiment.

YGW-18 welding wire was pickled hot rolled material with a diameter of 5.5 mm, then reduced to a diameter of 2.4 mm by cold drawing, coated with K ₂ CO ₃ , and pickled after annealing. A predetermined amount of copper plating layer was formed by electroplating. After plating, a powder lubricant mainly composed of Na soap was used, the diameter was reduced to 1.25 mm by roll rolling, and the diameter was reduced to 1.19 mm using a hole die. After washing, fats and oils, powder and K compound were uniformly applied to the wire surface.

The welding conditions with YGW-18 are bead-on-plate welding under the conditions that the shielding gas is 100% CO ₂ , the current is 340 A, the voltage is 36 V, the protruding length is 23 mm ± 2 mm, and the welding speed is 30 cm / min. . The steel plate to be welded was JIS SM490A (thickness 16 mm), and a thyristor power source was used as the welding power source. The performance evaluation results for YGW-18 are shown in Table 4 below.

  As shown in Table 4, in the cases of Examples 5 to 19 of the present invention, the generation amount of fumes was reduced as compared with the cases of Comparative Examples 1 to 4 which are out of the scope of the present invention. In particular, in Examples 8 to 19 in which the number of depressions was 100 or more, the amount of fume generation was further reduced.

It is a figure which shows the hollow shape of the wire surface in the cross section of a welding wire. It is a microscope picture which shows the hollow shape of the surface of this invention wire and a comparative example wire.

Explanation of symbols

1: Recess 2: Copper plating layer

Claims (12)

A solid wire for arc welding with copper plating in which a copper plating amount of 0.05 to 0.40% by mass is plated on the surface of the wire, and has a recess that opens in the cross section perpendicular to the longitudinal direction of the wire. 1 or 2 selected from the group consisting of vegetable oil, animal oil, synthetic oil and mineral oil in an amount of 0.1 to 2 g per 10 kg of wire, the number of these depressions being 40 to 400 in an arbitrary cross section of the wire Solid wire for arc welding with copper plating, characterized in that more than seed oil is present on the wire surface and in the opening of the recess. The solid wire for arc welding with copper plating according to claim 1, wherein the copper plating layer is present in a state of being folded in the recess. 3. The solid wire for welding with copper plating according to claim 1, wherein the number of the recesses is 100 to 400. 4. One or more kinds of powders selected from the group consisting of MoS ₂ , WS ₂ , and ZnS ₂ are present on the wire surface in an amount of 0.05 to 0.8 g per 10 kg of the wire. The solid wire for arc welding with copper plating according to any one of claims 1 to 3. One or two or more kinds of powders selected from the group consisting of MoS ₂ , WS ₂ , and ZnS ₂ are present in the depressions in an amount of 0.01 to 0.2 g per 10 kg of wire. The solid wire for arc welding with copper plating according to any one of claims 1 to 4. One or more powders selected from the group consisting of MoS ₂ , WS ₂ , and ZnS ₂ are present on the wire surface in an amount of 0.05 to 0.8 g per 10 kg of the wire, and at the same time the interior of the depression Further, 0.01 to 0.2 g of one or more powders selected from the group consisting of MoS ₂ , WS ₂ and ZnS ₂ are present per 10 kg of wire. 5. Solid wire for arc welding with copper plating according to any one of 4 above. K compound or Na compound is present in 0.01 or 10.0 mass ppm in terms of K amount or Na amount in one or a plurality of portions on the surface of the wire, the inside of the recess, and the surface of the steel, or the K compound And the Na compound is present in a total amount of 0.01 to 10.0 mass ppm when converted into K amount and Na amount, respectively, with copper plating according to any one of claims 1 to 6 Solid wire for arc welding. The said K compound and / or Na compound are 0.1 to 5 mass ppm in conversion of K amount and Na amount independently or in total amount, The arc welding with copper plating of Claim 7 characterized by the above-mentioned. Solid wire for use. Arc welding with copper plating according to any one of claims 1 to 8, characterized in that the center line average surface roughness Ra measured in the circumferential direction of the wire surface is 0.05 to 1.0 µm. Solid wire for use. The composition of the wire is as follows: C: 0.01 to 0.12% by mass, Si: 0.2 to 1.2% by mass, Mn: 0.5 to 2.5% by mass, P: 0.001 to 0.8%. The arc with copper plating according to any one of claims 1 to 9, characterized by containing 03 mass% and S: 0.001 to 0.03 mass%, with the balance being Fe and inevitable impurities. Solid wire for welding. The solid wire for arc welding with copper plating according to claim 10, wherein the composition of the wire further contains Ti + Zr: 0.03 to 0.3 mass%. The solid wire for arc welding with copper plating according to claim 11, wherein the composition of the wire further contains Mo: 0.01 to 0.6 mass%.

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