JP2009101376A - Welding wire with copper plating - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a welding wire with copper plating which generates little plating waste, has a good conducting property, and is excellent in feeding property. <P>SOLUTION: In the welding wire which is copper-plated on the surface of a steel wire, the concentration of copper and copper oxide in the wire surface is measured by X-ray photoelectric spectroscopy, and the existence ratio of copper oxide with respect to copper is calculated as a copper oxide ratio (atomic%). When the surface layer part having the copper oxide ratio of more than 6% is defined as a copper oxide enriched layer and the wire surface is sputtered using an argon laser beam, the depth of this copper oxide enriched layer is less than 10 nm from the wire surface in terms of the sputter rate using SiO<SB>2</SB>as a standard sample. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a copper-plated welding wire widely used for arc welding construction of welded structures such as vehicles, steel frames and bridges.

  Conventionally, in order to improve welding workability at the time of arc welding, it has been attempted to define the amount of oxygen on the surface of the arc welding wire.

  For example, as described in Patent Document 1, the average value of the detected oxygen concentration is specified to be 20 atomic% or less at a depth of 21.6 to 43.2 nm from the wire surface of an arc welding wire without plating. To do. By regulating the amount of oxygen, the surface tension and viscosity of the droplets are optimized to reduce the amount of spatter generated in arc welding.

  For example, as described in Patent Document 2, the amount of oxygen from the wire surface of the copper-plated arc welding wire with copper plating to a depth of 50 μm is defined within a predetermined range, and the copper plating thickness is set to 0.3 μm. It is defined below. By defining the amount of oxygen, the arc can be stabilized by optimizing the surface tension and viscosity of the droplet, and by defining the copper plating thickness, the effect is similar to increasing the amount of wire oxygen (arc Stabilization).

JP 2003-236694 A Japanese Patent Application Laid-Open No. 2002-239783

  However, the technique described in Patent Document 1 cannot be applied to an arc welding wire with copper plating. This is because the film thickness and oxygen amount of the oxide film in copper plating are completely different due to the difference in oxygen affinity between steel and copper. Further, in Patent Document 1, the amount of oxygen on the wire surface is measured, but the oxygen source cannot be specified. Therefore, the amount of oxygen due to wire surface contamination and the oxygen due to the oxygen concentrated layer are not determined. The amount cannot be separated. As a result, the regulation of the amount of oxygen on the wire surface does not define the amount of oxygen attributed to the oxygen-enriched layer from the wire surface to a depth of 20 nm. Accordingly, the welding workability cannot be sufficiently improved with an arc welding wire with copper plating.

  Moreover, in patent document 2, it does not isolate | separate a copper plating (0.3 micrometer) part and a steel material part about the oxygen concentration layer of the wire surface, but mainly explains the oxygen amount of the steel part, The amount of oxygen cannot be explained. If the amount of oxygen in the copper-plated portion is high, there is a problem that due to the formation of highly insulating copper oxide, the current on the wire surface is delayed, the welding current is not stable, and the arc becomes unstable. Further, since copper oxide has low ductility, there is a problem that the copper plating is peeled off in contact with the feeding roller and the liner during welding, resulting in generation of plating scraps and clogging, and the arc becoming unstable.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a copper-plated welding wire with less generation of plating scraps, good electrical conductivity and excellent feedability.

The welding wire with copper plating according to the present invention is a welding wire in which the surface of a steel wire is plated with copper. The concentration of copper and copper oxide on the surface of the wire is measured by X-ray photoelectron spectroscopy. When the abundance ratio is calculated as the copper oxide ratio (atomic%), and when the surface layer portion where the copper oxide ratio is 6% or more is defined as a copper oxide concentrated layer, the wire surface is sputtered using an argon beam Further, the depth of the copper oxide concentrated layer is 10 nm or less from the wire surface in terms of sputtering rate using SiO ₂ as a standard sample.

In the present invention, 0.01 to 0.80 g of one or more substances selected from the group consisting of MoS ₂ , WS ₂ , ZnS, graphite, and BN may be present on the wire surface per 10 kg of the wire.

  0.1 to 2.0 g of one or more oils and fats selected from the group consisting of mineral oil, animal oil, vegetable oil and synthetic oil may be present on the wire surface per 10 kg of the wire.

  INDUSTRIAL APPLICABILITY The present invention can provide a copper-plated arc welding wire with less generation of plating scraps, good electrical conductivity, and excellent feedability.

  Hereinafter, the present invention will be described in detail.

  Arc welding wires are generally pickled, pre-plated (hereinafter referred to as “primary wire drawing”), cleaning, plating, and finish wire drawing (hereinafter referred to as “secondary wire drawing”). It is manufactured through the process.

  First, the wire subjected to the pickling treatment until the scale is completely removed is first drawn to a predetermined wire diameter. Subsequently, after performing a cleaning process to remove the wire drawing lubricant adhering to the surface of the wire by primary wire drawing, a plating process is performed.

  In the plated wire, the plating plays the role of a lubricating film in the secondary wire drawing process. If the adhesion of the plating is not good, there is a risk that a lubrication failure occurs in the secondary wire drawing and the oxidation of the plating is promoted. is there. If the plating is too oxidized, the object of the present invention cannot be achieved. Therefore, obtaining good plating adhesion is a prerequisite for carrying out the present invention.

In order to improve the adhesion of the plating, it is important to perform a cleaning process before the primary wire drawing. That is, if the cleaning process is insufficient, the plating generation is hindered and the adhesion of the plating is deteriorated. Therefore, in the primary wire drawing process for producing the welding wire according to the present invention, K soap, Na soap, and Ba soap having excellent cleaning properties are used. Although it is also possible to apply Ca soap excellent in wire drawing lubrication performance, in that case, alkaline degreasing, annealing for the purpose of washing and pickling steps are required, which is not preferred because of cost problems. On the other hand, K soap, Na soap and Ba soap are relatively poor in lubricity. Therefore, it is preferable to add an extreme pressure agent or a softening point adjuster to obtain a lubricant having both lubricity and detergency. As the extreme pressure agent, MoS ₂ , WS, BN, ZnS, polytetrafluoroethylene, wax or graphite is appropriately blended in the lubricant. Further, as a softening point adjusting agent, at least one selected from Na phosphate, Na borate, Na nitrate, Na carbonate, K phosphate, K phosphate, K nitrate and K carbonate is used.

  Subsequently, a copper plating process is performed by adjusting the wire surface temperature, the dipping time in the plating bath, etc., and the semi-finished product thus plated is secondarily drawn to the final product diameter. It is this secondary wire drawing that has the greatest influence on the surface quality of the product, and it is most important in the present invention to suppress oxidation of the plating in this step.

  The inventors have conducted basic investigations on the temperature at which copper oxidation is promoted, and the surface of the secondary wire is oxidized when the wire surface temperature reaches 70 ° C. or higher, and the oxidation specified in the present invention. It has been found that a copper enriched layer is hardly generated. Further, it has been found that when the wire surface temperature exceeds 100 ° C., an oxide film is remarkably generated on the wire surface, and the copper oxide concentrated layer defined in the present invention cannot be obtained.

  Therefore, in order to produce the copper oxide concentrated layer defined in the present invention, it is necessary to maintain the wire surface temperature during processing at 100 ° C. or lower, desirably 70 ° C. or lower.

  Here, as means for maintaining the wire surface temperature at 100 ° C. or lower, it is effective to suppress the heat generation amount and to cool after the heat generation.

  First, suppression of heat generation will be described. Since the heat generation amount during processing is mainly governed by the processing rate, it is effective to suppress the processing rate in order to suppress the heat generation amount. Although the amount of heat generated varies depending on the deformation resistance of the wire, in general mild steel, it is possible to keep the wire temperature below a predetermined temperature by setting the die work area reduction to 34% or less, preferably 18% or less. Thus, a copper oxide concentrated layer defined in the present invention can be obtained. In particular, the degree of influence on the surface quality of the product by the reduction in area near the final product diameter is high. Therefore, it is desirable to reduce the area reduction rate to 15% or less in processing near the final product diameter.

  Further, by reducing the diameter of the wire to be plated, the total amount of processing from the plating to the final product diameter can be reduced, and the amount of heat generated can be suppressed. In the plating process, in order to secure a necessary plating amount, it is necessary to immerse the wire in the plating bath for a certain period of time. Therefore, there is an upper limit on the speed of the wire passing through the plating process. If the wire diameter for plating is made too fine, a sufficient amount of wire cannot be produced within the upper limit speed, and the productivity is significantly reduced. Therefore, it is necessary to set a range in which the plating diameter satisfies both productivity and oxidation state. In the present invention, the wire diameter for plating is set to φ1.7 mm to φ3.0 mm.

  Next, cooling after heat generation will be described. In a continuous wire drawing machine (hereinafter referred to as “continuous drawing machine”) in which 4 to 10 die blocks are continuously arranged, the wire surface tends to become hot as it approaches the product diameter. This is because the heat generated in the (N + 1) th and subsequent die blocks is sequentially added to the wire before the heat generated in the Nth die block is sufficiently cooled. Since the temperature near the product diameter should be kept at the lowest temperature, secondary wire drawing near the final product diameter does not use a continuous drawing machine, and a single die or a limited number of die blocks up to 3 at most. The continuous stretcher is desirable. However, if the number of die blocks is too small, it is necessary to perform secondary wire drawing a plurality of times, and productivity is extremely deteriorated. Therefore, in the present invention, the hook after the die drawing is sufficiently cooled, and a predetermined surface temperature is maintained by blowing cooling air at a high speed onto the wire surface immediately after the die processing. By this method, the copper oxide concentrated layer defined in the present invention can be obtained even with a continuous stretcher in which 4 to 10 die blocks are continuously arranged.

  Here, liquids such as general-purpose machine oil and water can be used as the cooling liquid, but it is desirable to use an organic solvent which is volatile and can obtain a high cooling effect by heat of vaporization. In the case of using an aqueous solution, the general water such as industrial water will promote oxidation and have an adverse effect. Therefore, it is necessary to suppress oxidation promotion by adjusting the pH of water, adding a reducing agent, and the like.

  When the amount of heat of processing is extremely large, such as low alloy steel, it is necessary to consider another method. That is, it is a technique in which a semi-finished product processed to near the finished product diameter is annealed in a reducing gas atmosphere. Although this method has a cost problem due to the addition of the annealing process, it is not necessary to consider the heat generation amount in the secondary wire drawing process, and the cleaning process of the lubricant used for wire drawing can be omitted. There is also an advantage, and it is an effective technique for obtaining a good oxidation state with a low alloy steel or the like.

  Next, the reason for limiting the numerical value of the present invention will be described.

"The depth of the copper oxide concentrated layer is 10nm or less from the wire surface"
Since copper oxide has high insulating properties, if the depth of the copper oxide concentrated layer is greater than 10 nm, there is a high possibility that current conduction during arc welding will be hindered, and feedability will be reduced. Moreover, since copper oxide has low ductility, it becomes easy to peel off by contact with a liner or the like, and clogging properties are reduced.

“One or more substances selected from the group consisting of MoS ₂ , WS ₂ , ZnS, graphite, and BN on the wire surface are 0.01 to 0.8 g per 10 kg of wire”
When the total amount of one or more kinds of substances selected from the group consisting of MoS ₂ , WS ₂ , ZnS, graphite, and BN is less than 0.01 g / 10 kg of wire, the slipperiness of the wire is not improved and the feedability is inferior. Further, if the amount of the substance is more than 0.8 g, there is a risk that these solid lubricants are clogged inside the liner.

“One or more oils and fats selected from the group consisting of mineral oil, animal oil, vegetable oil and synthetic oil on the wire surface are 0.1 to 2.0 g per 10 kg of wire”
If the oil and fat is less than 0.1 g / 10 kg of wire, the slipping property of the wire is deteriorated and the feeding property is inferior. On the other hand, when the amount of oil is more than 2.0 g, problems such as clogging of oil and fat inside the liner and slipping of the wire by the feeding roller occur.

  Hereinafter, the effect of the Example of this invention is demonstrated compared with the comparative example which remove | deviates from this invention.

  First, a sample evaluation method will be described. Table 1 below shows this evaluation standard.

"Welding conditions"
A commercially available feeding device for arc welding having two bent portions between 6 m was used for the evaluation of the electric conductivity and the feeding property. An arc welding test was conducted with a CO ₂ gas shielded welder, and the experimental results were evaluated. The welding conditions were a downward bead on, a protruding length of 25 mm, a welding speed of 30 cpm, and an arc time of 15 minutes.

"Evaluation of electrical conductivity"
Measurements were made for current ranges 180A and 280A. The current region 180A is a short-circuit transition region, and the voltage always changes with a constant fluctuation range. When energization instability occurs during welding, the voltage fluctuation range fluctuates significantly compared to that during stable welding. Here, in this invention, when the voltage value was set to 30V or less, it was thought that the electricity supply failure generate | occur | produced, and the frequency | count of the electricity supply failure which generate | occur | produced during welding for 15 minutes was measured. And as shown in Table 1 below, when the number of energization failures is 0 to 1, the conductivity is very excellent (◎), and when it is 2 to 5 times, the conductivity is excellent (○ ), In the case of 6 to 12 times, the conductivity was evaluated as a reference level (Δ), and in the case of 13 times or more, the conductivity was evaluated as inferior (x).

  Since the current region 280A is a globule transition form, a short circuit may occasionally occur between the molten pool and the welding wire, and the voltage may drop instantaneously. Therefore, in the present invention, it was considered that an energization failure occurred when the welding voltage became 5 V or less, and the number of energization failures was measured during welding for 15 minutes. And as shown in following Table 1, when the frequency | count of an electrical conduction failure is 0-3 times, electrical conductivity is very excellent ((double-circle)), and when 4-10 times, electrical conductivity is excellent ((circle) In the case of 10 to 20 times, the electrical conductivity was evaluated as a reference level (Δ), and in the case of 20 times or more, the electrical conductivity was evaluated to be inferior (x).

"Evaluation of transportability"
A load cell was incorporated in the feed roller, and the feed resistance received from the wire by the feed roller was measured. As shown in Table 1 below, in the current region 180A, when the feed resistance (kgf) is 0.0 to 1.5 (kgf), the feedability is very excellent (◎). In the case of 5 to 2.5 (kgf), the feedability is excellent (◯), and in the case of 2.5 to 4.0 (kgf), the feedability is the reference level (Δ), 4.0 or more. In some cases, the feedability was inferior (x). On the other hand, in the current region 280A, when the feeding resistance is 0.0 to 2.0 (kgf), the feeding property is very excellent (◎), 2.0 to 4.0 (kgf). In the case of excellent feedability (◯), in the case of 4.0 to 6.0 (kgf), the feedability is the standard level (Δ), and in the case of 6.0 or more, the feedability is inferior. (×).

"Evaluation of clogging"
Two loops with a diameter of 300 mm were made on a 1.5 mm liner, and 10 kg of wire was fed to a feeding path arranged in an 8-shape. By measuring the amount of increase in liner weight generated in this case by the differential method, the amount of clogging generated inside the liner during the feeding and deposits on the surface of the wire dropped off and clogged in the liner was measured. . Based on this weight, the clogging property was evaluated as shown in Table 1 below. Specifically, when the amount of the clogged material with respect to 10 kg of wire is less than 0.0200 (g), the clogging property is very excellent (（), and the amount of the clogged material is 0.0200 to 0.0700. In the case of (g), the clogging property is excellent (◯). In the case of 0.0700 to 0.1200 (g), the clogging property is clogged when the clogging property is a reference level (Δ) or more than 0.1200 (g). The quality was inferior (x).

  Next, a method for manufacturing a sample will be described. First, a strand subjected to pickling with hydrochloric acid until the scale was completely removed was first drawn to a total diameter of 1.8 mm. The chemical composition of the used wire is JIS YGW11 and YGW12. Table 2 below shows specific examples of the component composition of the solid wire actually used for the test evaluation. In addition, a unit is mass%, and Tr shows that it is a trace amount (Trace).

For the primary wire drawing, K soap was used. At this time, MoS ₂ , WS, BN, ZnS, polytetrafluoroethylene, wax or graphite was used in appropriate combination as an extreme pressure agent. As the softening point adjuster, carbonic acid K and boric acid K were blended in an amount of 10 wt% with respect to the soap weight.

  Subsequently, the wire drawing lubricant adhering to the wire was washed with water kept at a temperature of 40 ° C. or higher, and then the copper plating treatment was performed by adjusting the wire surface temperature, the dipping time in the plating bath, and the like.

  In the secondary wire drawing of the example, the wire surface temperature was maintained at 90 ° C. or lower.

  Specifically, the reduction in the processing area of all dies is 25% or less, especially 15% or less in the vicinity of the final product diameter, and the copper-plated semi-finished product is subjected to secondary wire drawing to the final product diameter (finishing) Drawn).

  Further, the water after cooling to 5 ° C. or lower was used to sufficiently cool the pot after drawing the die, and further, cooling air was blown onto the wire surface immediately after the die processing at a high speed to maintain a predetermined wire surface temperature.

  About the comparative example, these cooling processes were not performed but the wire under process was drawn with the temperature being high.

Table 3 below shows the results of measuring the depth at which the Cu Oxide Rate is 6% or more for Samples 1 to 7 produced in this manner. Further, MoS ₂ , WS ₂ , ZnS, graphite, BN, and feed oil applied to Samples 1 to 7 were classified, and samples 1- were evaluated for the conductivity, feedability, and clogging properties for each of the classified wires. It describes as 1-7-4. Further, in the present invention, XPS (ULVAC-PHI: Quantera SXM, X-ray source Al monochromatic line: 1486.6 eV) is used, and in the depth direction, the amount of oxygen on the wire surface and the depth of the copper oxide concentrated layer Was measured. The measurement conditions were an X-ray probe diameter of 100 μm, Ar sputter 1 kV2 × 2 (calculate the sputter rate with a 100 nm SiO ₂ film before this measurement), and CuLMN and Cu ₂ p3 were obtained at a photoelectron extraction angle of 45 °. . The abundance ratio was calculated in terms of atomic% from the spectrum area ratio, where the outermost CuLMN spectrum was copper oxide and the innermost CuLMN spectrum was metal Cu.

  FIG. 1 is a cross-sectional view of an arc welding wire 1 according to the present invention. As shown in the figure, a copper plating 20 is applied to the surface of the steel material 10.

  FIG. 5 shows the measurement results of the copper oxide ratio (atomic%) with the vertical axis representing the copper oxide ratio (Cu Oxide Rate) (atomic%) and the horizontal axis representing the depth (nm) from the wire surface. As shown in the figure, in samples 1 to 7, the depth (nm) at which the copper oxide ratio (atomic%) is 6% or more is 12.0 nm (sample 1), 10, 5 nm (sample 2), They were 10.5 nm (sample 3), 7.0 nm (sample 4), 6.8 nm (sample 5), 6.0 nm (sample 6), and 4.0 nm (sample 7). Samples 1 to 3 have a depth (nm) larger than 10 nm at which the copper oxide ratio (atomic%) is 6% or more, and are comparative examples outside the scope of the present invention. Samples 4 to 7 have a depth (nm) of 10 nm or less at which the copper oxide ratio (atomic%) is 6% or more, and are examples within the scope of the present invention.

  FIG. 2 is an enlarged view of a copper plating portion of the example (samples 4 to 7). As shown in the figure, the copper plating is performed at a depth of 100 nm to 2000 nm, and the copper oxide is distributed at a depth of 20 nm to 50 nm. And the thickness of the copper oxide concentrated layer from which a copper oxide ratio (atomic%) will be 6% or more is 10 nm or less.

  On the other hand, FIG. 3 is an enlarged view of the copper plating portion of the comparative example (samples 1 to 3). As shown in the figure, the copper plating is performed at a depth of 100 nm to 2000 nm, and the copper oxide is distributed at a depth of 20 nm to 50 nm. And the thickness of the copper oxide concentrated layer in which the copper oxide ratio (atomic%) is 6% or more is larger than 10 nm.

These samples 1 to 7 are prepared by applying a predetermined amount of a lubricant containing one or more substances selected from the group consisting of MoS ₂ , WS ₂ , ZnS, graphite, and BN and those not applied. did. And using these samples 1-7, as shown in FIG. 4, arc welding was performed and the electrical conductivity, feeding property, and clogging property were evaluated. In addition, about the feeding property, it evaluated by both YGW11 and YGW12.

  Table 3 below shows the test results. As shown in Table 3, none of the samples 1-1 to 3-2 (comparative examples) could be evaluated as having no problem with respect to conductivity, feeding property, and clogging. For all samples, either was a reference level (Δ) or inferior (x) evaluation.

  Since YGW12 has a low welding speed and the required electrical conductivity and feedability are not relatively severe, all the samples were able to satisfy the electrical conductivity and feedability. In particular, Samples 7-1 to 7-4 having a thin copper oxide concentrated layer were able to satisfy the electrical conductivity and the feedability without including a solid lubricant in the coating oil. In Sample 7-1, it was possible to satisfy excellent feedability and electrical conductivity simply by adding a small amount of solid lubricant. In Sample 4-1, the copper oxide concentrated layer was particularly thin, and the slipperiness with a small amount of solid lubricant was good, so that the clogging property was particularly excellent.

  As shown above, a good correlation was recognized between the electrical conductivity, the feeding property, the clogging property, and the copper oxide ratio (atomic%).

  For comparison with the copper oxide ratio (atomic%), we will also examine the correlation between oxygen concentration and electrical conductivity, feedability, and clogging. FIG. 6 shows the measurement results of the oxygen concentration (atomic%) where the vertical axis represents the oxygen concentration (atomic%) and the horizontal axis represents the depth (nm) from the wire surface. From the experimental results shown in FIG. 3 and Table 3, a rough correlation is also found between the oxygen concentration and the conductivity, feedability, and clogging properties. However, the correlation between the sample 2 and the sample 4 is broken. Here, from the experimental results of FIGS. 5 and 6, the oxygen amount of the sample 2 is relatively low, but the copper oxide ratio (atomic%) is high, and the oxygen amount of the sample 4 is relatively high, but the copper oxide ratio is high. It can be seen that (Atom%) is low.

  Paying attention to Samples 2 and 4, the residual amount of each element on the wire surface was measured by X-ray photoelectron spectroscopy in order to identify the oxygen source that improves the correlation with the electrical conductivity, feedability, and clogging properties. . 7 and 8 show the measurement results of Sample 2 and Sample 4. FIG. As shown in FIG. 7, the sample 2 has a relatively small amount of organic matter on the wire surface, whereas as shown in FIG. 8, the sample 4 has a relatively large amount of organic matter on the wire surface. From the measurement results of FIG. 7 and FIG. 8, the oxygen content of the sample 4 is higher than that of the sample 2 due to the influence of oxygen contained in organic matter such as fats and oils. And since the oxygen amount of this sample 4 is relatively high, the ratio of copper oxide (atomic%) is relatively low. It can be said that it is oxygen.

  Therefore, it can be said that by specifying not the oxygen amount but the copper oxide ratio (atomic%), it is possible to obtain an arc welding wire with good electrical conductivity, feedability and clogging properties.

It is sectional drawing of the arc welding wire which concerns on this invention. It is an enlarged view of the plating part of the arc welding wire which concerns on the Example of this invention. It is an enlarged view of the plating part of the arc welding wire which concerns on the comparative example of this invention. It is the figure which showed the electricity supply method to the arc welding wire which concerns on this invention. It is the figure which showed the measurement result of the copper oxide ratio (atomic%) of the arc welding wire surface which concerns on this invention. It is the figure which showed the measurement result of the oxygen concentration (atomic%) of the arc welding wire surface which concerns on this invention. It is the figure which showed the measurement result of the residual amount of each element of the wire surface of the sample 2 which concerns on this invention. It is the figure which showed the measurement result of the residual amount of each element of the wire surface of the sample 4 which concerns on this invention.

Explanation of symbols

1 Arc welding wire 10 Steel 20 Copper plating

Claims (3)

In a welding wire with copper plating on the surface of the steel wire, the copper and copper oxide concentrations on the wire surface are measured by X-ray photoelectron spectroscopy, and the copper oxide to copper ratio is defined as the copper oxide ratio (atomic%). When the surface layer portion where the copper oxide ratio is calculated to be 6% or more is defined as a copper oxide concentrated layer, when the wire surface is sputtered using an argon beam, sputtering using SiO ₂ as a standard sample A copper-plated welding wire characterized in that the depth of the copper oxide concentrated layer is 10 nm or less from the wire surface in terms of rate. 2. The wire surface according to claim 1, wherein one or more substances selected from the group consisting of MoS ₂ , WS ₂ , ZnS, graphite, and BN are present in an amount of 0.01 to 0.80 g per 10 kg of the wire. Welding wire with copper plating.   3. The oil according to claim 1, wherein at least one oil selected from the group consisting of mineral oil, animal oil, vegetable oil, and synthetic oil is present on the wire surface in an amount of 0.1 to 2.0 g per 10 kg of the wire. Welding wire with copper plating as described.

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