JPS6313696A - Production of welding wire - Google Patents

Abstract

PURPOSE:To stabilize an arc and to improve a droplet transfer characteristics at the time of welding by subjecting a wire surface to a chemical conversion treatment to form a layer of an oxygen compd. thereon, then plating copper to the oxygen compd. layer. CONSTITUTION:After the stock wire is degreased in a degreasing tank 1, the surface is cleaned by a pickling tank 2 and the wire is subjected by dipping, etc., to the chemical conversion treatment such as phosphate treatment or anodic oxidation treatment with an oxalic acid in a chemical conversion treatment tank 3. The wire W formed with the oxygen compd. on the surface is rinsed and thereafter, the remaining oxygen compd. layer is subjected to copper plating such as copper pyrophosphate plating or copper cyanide plating. Since the oxygen compd. layer is porous, the plating having the good adhesiveness is possible. The oxygen compd. layer having a uniform oxygen concn. is formed on the wire surface and since the copper plating layer having good electrical conductivity exists thereon, the arc is stabilized and the droplet transfer characteristic is improved.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing a welding wire that has good droplet transfer properties during welding and is capable of obtaining a stable spray arc. .

[Prior art] A technology that allows the droplets formed at the tip of the wire during arc welding to spread smoothly over the base metal, thereby improving arc stability and further improving so-called welding workability in general, such as reducing spatter. Various types of bacteria have been reported for which it is effective to increase the oxygen concentration in the wire surface layer, and there are also descriptions of their manufacturing methods (Japanese Patent Laid-Open No. 60-162595, Japanese Patent Laid-Open No. 60-27492, Kaisho 59-110496.
JP 59-104292° JP 59-97794
, JP-A-59-85397, JP-A-59-61592
, JP-A-59-66996, JP-A-58-1926
94, JP-A-60-40 [i85, etc.).

[Problems to be Solved by the Invention] However, all of the techniques described in the above publications involve forming an oxide layer on the surface layer of the wire by heat treatment or applying an oxide to the surface of the wire. This leaves some problems.

The method of forming an oxide layer by heat treatment requires extremely large-scale equipment to obtain a uniform oxide layer, and also requires strict control of manufacturing conditions such as atmosphere adjustment.

On the other hand, there is a method of coating the wire surface with an oxide, which simplifies the equipment, but is still insufficient in terms of uniformity of oxygen concentration.

In view of the above-mentioned problems, the present invention provides melting during welding.

[Means for Solving the Problems] The method of the present invention that can solve the above problems is to apply a chemical conversion treatment to the wire surface to form an oxygen compound layer, and then leave the oxygen compound layer to remain. The gist is to perform copper plating in the same condition.

[Function] In the method of the present invention, an oxygen compound layer is formed on the wire surface by chemical conversion treatment, and copper plating is applied thereon with the oxygen compound layer remaining. Therefore, the oxygen concentration in the oxygen compound layer is can be easily made uniform in terms of arithmetic average without using large-scale equipment, and the drawbacks of the prior art are eliminated at once. Although it is inevitable that the presence of the oxygen compound layer deteriorates the electrical conductivity of the wire surface, the electrical conductivity can be sufficiently restored by applying copper plating to the surface. Therefore, a welding wire is obtained that has good droplet elegance during welding and can produce a stable spray-like arc.

FIG. 1 is a schematic explanatory diagram of the manufacturing process according to the present invention. The raw wire W is first passed through a degreasing tank 1, then washed with water, and then passed through a pickling tank 2.
Clean the surface by passing it through the water, then rinse with water. Next, a chemical conversion treatment is performed in a chemical conversion treatment tank 3 to form an oxygen compound layer, followed by washing with water, and then passed through a copper plating tank 4 for copper plating treatment, followed by washing with water. Then, the wire is passed through a hot water washing tank 5 for finishing cleaning, then passed through a wire die 6, and drawn to a predetermined diameter to obtain a welding wire.

Chemical treatment includes phosphate treatment and thiosulfuric acid treatment.

Oxalic acid anodic electrolytic treatment 1 Alkaline black oxidation treatment.

Chemical conversion treatments such as these are applied to bare wires to form an oxygen compound layer on the wire surface, and there are no particular limitations on these treatments or the conditions under which they are carried out.

This chemical conversion treatment is performed by immersing the wire in the chemical conversion treatment liquid in the chemical conversion treatment tank 3 or by spraying the chemical conversion treatment liquid onto the wire using a sprayer, etc., and the equipment is extremely simple and the equipment cost is low. In addition, liquid immersion treatment or I]
Since it is a lJn treatment, compared to heat treatment methods and oxide coating methods,
The oxygen concentration in the oxygen compound layer becomes uniform. Furthermore, the chemical conversion treatment conditions can be easily managed, and changes due to differences in the composition or type of wire can be easily accommodated without changing the treatment conditions. Although oxalic acid anodic electrolytic treatment requires electrical equipment, it has the advantage of shortening the chemical conversion treatment time.

Furthermore, the oxygen compound layer referred to here does not need to be formed uniformly and with a constant layer thickness, but rather may have partial or microscopic differences in layer thickness, or may fall off or tear in some parts. It is more advantageous to exhibit an anchoring effect when the surface of the substrate is oxidized, and the important thing is that the surface oxygen concentration is uniform on an arithmetic average basis.

Copper plating is performed on the oxygen compound layer thus formed while it remains. However, copper plating may be performed after adding light treatments such as water washing and skin pass. Copper plating methods include copper cyanide plating, copper sulfate plating, copper pyrophosphate plating, etc. Any plating may be used, but consideration should be given to the combination with the means used in the chemical conversion treatment process. It is preferable to select the In this case, copper pyrophosphate plating is better for phosphate-treated membranes, and copper bronze plating is better for oxalic acid anodic electrolytic membranes, in that copper plating with particularly good adhesion can be obtained. There is.

Until now, it was common knowledge that the surface of the wire should be activated as much as possible before plating, so the technical idea of plating on a wire that had been formed with an oxygen compound layer through chemical conversion treatment was There wasn't. However, according to the inventor's intensive research, the surface of this oxygen compound layer is microscopically porous (partially falling off and tearing), as mentioned above.
It was found that it was possible to perform plating with good adhesion because of this.

Furthermore, plating provides the following advantages.

■It is better in terms of preventing rust than leaving the oxygen compound layer as it is.

■Increasing the thickness of the oxygen compound layer improves the rust prevention effect and makes it equivalent to copper-plated wire, but the electrical conductivity with the chip becomes insufficient, especially when welding continuously for long periods of time at high currents. In some cases, the arc becomes unstable, so from the point of view of current conductivity, it is better to make it slightly thinner (0.5 to 1 μm).

In addition, as a raw wire, we use a wire that is slightly thicker than the product diameter, and eventually reduce it to the wire diameter in addition to a skin pass.
For wires with a larger diameter, several stages of dicing may be performed to obtain the finished product diameter.

Furthermore, if the surface is sufficiently activated by degreasing and pickling once or more, the chemical conversion treatment will be uniform and the adhesion of the chemical conversion film will be better. Furthermore, here, chemical conversion treatment is performed just before copper plating, but it seems that chemical conversion treatment is performed on a larger diameter, and after several stages of die pulling, degreasing and pickling are performed, and then copper plating is performed. You can also do it. However, in this case, it is better to lightly degrease and pickle before copper plating, and for this purpose, for example, if dry wire drawing is used, a lubricant with as good degreasing properties as possible should be used, or wet wire drawing is preferable.

The method of the present invention is applied to soft and hard steel, 50 kg class high tensile strength steel, 60 kg class or higher high tensile strength steel, low temperature steel, and Cr-M.

It is applicable to solid wires and flux-cored wires used for welding various steel types such as steel and stainless steel.

[Examples and Comparative Examples] (Example 1 and Example 2) Transposition plating was performed by performing chemical conversion treatment under the following conditions to form an oxygen compound layer on the surface of the bare wire. Table 1 shows the surface oxygen concentration measurement results.

Wire type: JTS Z 3312, YGW16 applicable product Chemical treatment method: Phosphate treatment Chemical treatment solution: Commercially available phosphate treatment solution concentration: 5%, pH: 3.5 Solution temperature: 50 to 70°C Immersion time 30 seconds (implemented) Example 1) 60 seconds (Example 2) Copper plating method: Copper pyrophosphate plating (Example 3) Transposition plating in which a chemical conversion treatment was performed under the following conditions to form an oxygen compound layer on the surface of the bare wire. was applied. Table 1 shows the surface oxygen concentration measurement results.

Wire type: JIS Z 3312, YGW16 applicable chemical conversion treatment method: oxalic acid anode electrolysis treatment chemical conditions: electrolytic bath (COOH) 2 3% current density D
A 50A/dm" Liquid temperature 40 to 50°C Processing time 20 seconds Copper plating method: Copper bronze plating Although not shown in the chemical conversion treatment tank 3 in FIG. 1, in the case of Example 3, the wire There is an energizing equipment for electrode plate O.

(Comparative Example) A bare wire was heat treated under the following conditions. At this time, in order to make the oxygen compound layer uniform, sufficient consideration was taken such as adjusting the atmosphere. Table 1 shows the surface oxygen concentration measurement results.

Wire type 2 Same as above Heat treatment method: Strand method % formula % (Results) As is clear from Table 1, in the examples according to the method of the present invention, the variation in surface oxygen concentration was smaller than in the comparative example according to the heat treatment method, and the wire surface It can be seen that the average oxygen concentration is uniform.

[Effects of the Invention] As described above, according to the method of the present invention, an oxygen compound layer with a uniform oxygen concentration is formed on the wire surface, and a copper plating layer is further formed on the wire surface, so that droplet transfer during welding is prevented. A welding wire with good properties and a stable arc can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing a wire manufacturing process according to the present invention. 1... Degreasing tank 2... Pickling tank 3... Chemical conversion treatment tank 4... Copper plating tank 6... Dice

Claims (3)

[Claims] (1) A method for manufacturing a welding wire, which comprises performing a chemical conversion treatment on the wire surface to form an oxygen compound layer, and then performing copper plating with the oxygen compound layer remaining. (2) The welding wire according to claim 1, wherein the wire surface is subjected to phosphate treatment to form a phosphate film layer, and then copper pyrophosphate plating is performed with the phosphate film layer remaining. manufacturing method. (3) Welding according to claim 1, in which the wire surface is subjected to oxalic acid anodic electrolysis treatment to form an anodized film layer, and copper bronze plating is performed with the anodic oxide film layer remaining. Method of manufacturing wire.