JPH0242039B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a method for manufacturing a solid wire used in gas metal arc welding, and in this specification,
This paper proposes a technology that uses an appropriate lubricant to continuously produce wire-drawn products from strands to the final wire diameter without going through annealing or plating steps. (Prior art) The general method for manufacturing welding wire is to first remove scale from the surface of a wire manufactured by hot rolling, coat it with a wire drawing pretreatment agent, and draw the wire to an intermediate diameter. the first wire drawing process, the annealing process to remove the work hardening caused by the first wire drawing, the pickling and plating process, the second wire drawing process (finish wire drawing) to finish the product diameter, and finally the rewinding and packaging. The manufacturing process is divided into 7 steps. In the case of the conventional manufacturing method described above, the following problems have been pointed out. (1) Work efficiency is low because the work process is segmented. (2) Manufacturing takes a long time due to the annealing process. (3) Manufacturing costs are high. (4) Since copper plating is applied, large equipment and costs are required for waste liquid treatment. In view of the above-mentioned circumstances, there are the following conventional techniques aimed at solving the problem. For example, JP-A-55-54296
No. 1 describes a method for manufacturing wires continuously in a short time by drawing the raw wire without annealing it in the middle. Although this method allows for continuous wire drawing, it does not omit plating, so the drawback (4) above remains, and there is no consideration given to variations in tensile strength or arc stability, so it is difficult to weld. It is hard to say that this technology is actively making improvements to improve workability. Additionally, there is Japanese Patent Application Laid-Open No. 151197/1983 as a conventional technique that also adopts a continuous process, but this method
Since there is an annealing and plating process, the disadvantages of (2), (3), and (4) above remain, and the advantage of simplifying the manufacturing process is diminished. Furthermore, the technology proposed as Japanese Patent Publication No. 58-43195 specifies the wire components, especially the amounts of C, Si, and Ti.
Although this method enables wire drawing up to the product diameter, it is applicable only to the above-mentioned limited component systems, and improvements in wire feeding performance and power feeding performance are not discussed. (Problems to be Solved by the Invention) The present invention eliminates the annealing process that takes manufacturing time and costs, which were pointed out in the prior art, and eliminates the plating process that has problems such as waste liquid treatment. The purpose is to make the work from strands to finished wires continuous. And with this,
By simplifying the work process, we have reduced manufacturing costs, shortened manufacturing days, and omitted the plating process, which means that copper powder is not clogged in the conduit tube during welding due to no copper plating. be. (Means for Solving the Problems) The idea behind the present invention is to omit the annealing process and the plating process, and to make the process continuous. However, due to this, for example, if the annealing process is omitted, variations in tensile strength during hot heating may remain, leading to uneven feeding performance when feeding the wire.
Also, by omitting the plating process, the power supply resistance increases,
In particular, a problem arises in that uniform feeding is difficult due to the wire fusion phenomenon at the tip. In view of this, the present invention employs the following means to overcome this problem. That is, when drawing a wire with a wire diameter of 4.5 to 5.5 mφ that has undergone a pickling process using multiple dies without going through an annealing and plating process, it is necessary to use two lubricants as a lubricant in the dies at the initial stage of wire drawing. A wire drawing lubricant containing 3 to 15% of molybdenum sulfide or boron nitride shall be used, and at least an oil-based lubricant containing a power supply improver and an arc stabilizer shall be used as the lubricant in the final die. The area ratio is 2 to 12%, and the power supply improver and arc stabilizer remaining on the wire product surface are 50 to 300 ppm each.
We propose a method for producing solid wire for welding, which consists of a continuous process in which the wire is drawn under conditions satisfying the range of 10 to 300 ppm, and then re-wound. By using a lubricant containing 3 to 15% molybdenum disulfide or boron nitride in the first die and the second die as a wire drawing lubricant during the wire drawing stage, for example, the insufficiency of the annealing and plating steps can be eliminated. I decided to supplement this with a lubricant coating.
Furthermore, regarding the oil-based lubricant used for the final die, 50~
300 ppm, and as an arc stabilizer, one containing a power supply improver and an arc stabilizer is used so that 10 to 300 ppm remains. (Function) A feature of the present invention is that the wire is directly drawn without going through an annealing/plating process, and four steps up to the rewinding process are performed continuously. When such continuous wire drawing is performed, the wire itself undergoes work hardening, resulting in extremely poor wire drawability. However, according to the research of the present inventors, in the initial stage of wire drawing, for example, in the first die and the second die, a lubricant containing 3 to 15% of molybdenum disulfide or boron nitride, which has an effect equivalent to this, is applied. It has been found that using the agent enables wire drawing without reducing wire drawability. On the other hand, when wire drawing is performed continuously using a dry lubricant, a large amount of the drawing lubricant remains on the wire surface, so when the wire is fed during welding, the lubricant adheres to the inside of the conduit tube and the wire is fed. As a result of experiments, it has become clear that the residual lubricant impedes the power supply and further deteriorates the power supply performance at the welding chip, deteriorating the supply performance and inhibiting welding workability (arc stability). Based on these facts, the present inventors focused on improving the lubricant in the final wire drawing die and its area reduction rate. In other words, the lubricant is an oil-based lubricant (e.g. refined products of palm oil or olive oil) that has rust prevention and lubrication properties, and also contains a power supply improver (e.g. carbon, etc.) and an arc stabilizer (e.g. alkali). The wire drawing was conducted at a reduction rate of 2 to 12%. First of all, the reason why an oil-based lubricant was selected in the present invention is that, as is clear from Fig. 3, it is suitable for removing the dry lubricant that remains attached in the previous process, and it prevents residue from remaining in the conduit tube. less things,
This is because it has superior rust prevention and lubrication effects than dry lubricants. Note that if it is desired to further enhance the removal effect of the dry lubricant or the effect of adding an arc stabilizer or the like, it is preferable to use the same lubricant for the die in the previous step. Next, a power supply improving agent to be included in such an oil-based lubricant will be described. Improving wire feedability is an effective way to improve welding workability, but wire lubricity alone does not affect wire feedability within the conduit tube; power supply conditions also affect wire feedability. It has become clear that this has an effect on the feeding performance. As shown in Fig. 4, when comparing the armature current when only the wire is fed during non-welding with the wire feeding amount constant, that is, when the wire is fed in the inching state, and when the wire is fed by the feed motor during welding, It can be seen that the former is smaller. In other words, in the inching state, the current fluctuations are small and the wire is fed uniformly, but during welding, the fluctuations suddenly become large, and the power feeding state at the power feeding chip greatly affects the feeding performance, and this fluctuation If it becomes large, in extreme cases it will adversely affect weldability such as knotting phenomenon and wire clogging. Therefore, as in the present invention, it is desirable to further improve the power supply performance, especially when there is no medium such as copper plating that helps power supply. Regarding this point, the present inventors' research has found that it is effective to include an appropriate amount of a power supply improving agent, such as carbon, on the wire surface. Regarding the amount of addition, the higher the amount is, the better it is in terms of the power feeding effect, but if it is too large, it will have an adverse effect such as residue remaining in the conduit tube, so from FIG. 5, the lower limit was set to 50 ppm, and the upper limit was set to 300 ppm. Next, let's talk about arc stabilizers. In order to improve welding workability, it is necessary to maintain the stability of the arc itself in addition to wire feeding performance. for that purpose,
It is effective to leave elements with low ionization voltage on the wire surface to promote the generation of metal ions and maintain stabilization of the arc length. Alkali metals (Li, K, Cs, etc.) are suitable for this purpose. In this way, by adding an arc stabilizer, the sixth
As shown in the figure, the number of short circuits (short circuit transition region) increases, fine droplets migrate, and the arc becomes stable.
As for the amount added, it is effective to add 10 ppm or more, and the upper limit was set at 300 ppm in consideration of the power feeding improver and the fact that it does not impede the feeding performance. It is known that the tensile strength of the wire is related to the wire feeding performance and also affects the stability of the arc. Therefore, it is necessary to manufacture wires with uniform tensile strength. In this point, it is extremely difficult to maintain uniform tensile strength in the continuous wire drawing process, and the standard deviation (σ value) value
It was difficult to manufacture one with a rate of less than 1.2 Kgf/mm ² per 10 m. This non-uniform tensile strength: i.e. σ = 1.2Kg
At f/mm ² or more, as shown in Figure 7, there is still a problem with feeding performance, so as a result of studying to maintain σ < 1.2, we found that it is effective to remove the retained heat during wire drawing. It can be seen that it is. Finally, the reason for limiting the area reduction rate range will be described. The area reduction rate of 2% or more and 12% or less is 2%.
This is because if it is less than that, the area reduction rate is small, so much lubricant oozes out onto the product surface, and the amount of lubricant deposited tends to be uneven. On the other hand, if it exceeds 12%, the die life will be significantly reduced because the wire has already undergone considerable work hardening, and the amount of additives in the lubricant will reach the limit at which it can be maintained constant. be. Table 1 summarizes the above results.
The one that satisfies all of the above conditions is the most effective.

[Table] *Each factor is an item in the scope of claims, and ○ and × are within the range.
It shows the difference between good and bad. Furthermore, the effect seems to be good.
The value is 5, and the lower it is, the worse it is.
(Example) Based on FIG. 1, the manufacturing method of the present invention will be explained in comparison with the conventional manufacturing method (FIG. 2). First, in the case of the present invention, a hot rolled wire rod (strand) 1 is passed through pickling 2 and oil-based lubricant coating 3 steps,
The wire is then guided to a wire drawing machine 4 arranged in tandem that draws the wire to the diameter of the final product, and finally fed to a rewinding machine 8 to form a product. In this respect, in the conventional wire, as shown in FIG. 2, the wire 1 is scaled 1a, drawn in a primary wire drawing machine 1b, annealed 1c, pickled 1d, and plated 1e. It is necessary to go through a number of steps such as performing secondary wire drawing 9' to obtain the final wire diameter. Now, to explain the method of the present invention in more detail, first, 5.5 mmφ hot rolled wire rod 1 (JIS Z
3312YGW-12) was pickled, coated with an oil lubricant (3), passed through ten wire drawing dies (4), drawn at a wire speed (1.2 mmφ) of 500 m/min, and then rewinded (5). At this time, the first die uses a dry lubricant of 7% molybdenum disulfide, 50% calcium stearate, and the remaining lime, and the final die uses an olive oil-based oil lubricant, carbon as a power supply improver, and lithium carbonate as a stabilizer. +Potassium carbonate was used, and the wire was drawn to 1.2 mm at an area reduction rate of 7.2%, and the wire drawing residual amounts were 120 ppm of the power supply improver and 208 ppm of the arc stabilizer. In addition, the wire tensile strength at this time was an average of 112 Kgf/mm ² for 10 m of wire, and a standard deviation of 0.8.
It was Kgf/ ^mm2 . The results of welding tests using the above wires are shown in Table 2, and favorable results were obtained in all cases.

[Table] (Effects of the invention) As explained above, according to the present invention, since no annealing is performed, the manufacturing process is simplified, manufacturing efficiency is high, and costs are reduced.In addition, since copper plating is not applied, the wire is fed easily. A solid wire for welding which is free from clogging and exhibits good weldability can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of the manufacturing process of welding wire according to the present invention, Fig. 2 is a schematic diagram of the manufacturing process of welding wire according to the conventional method, and Fig. 3 is a schematic diagram of the manufacturing process of welding wire according to the present invention. A graph showing the influence of the amount of wire used on the amount of residue, FIG. 4 is a graph showing the influence of power feeding on wire feedability, FIG. 5 is a graph showing the effect of the power feeding improver, and FIG. FIG. 7, a graph showing the effect of the arc stabilizer, is a graph showing the effect of tensile strength and variation on wire feedability. 1... Wire (strand), 2... Pickling process, 3...
...Coating process, 4...Wire drawing process, 5...Rewinding process.

Claims (1)

[Scope of Claims] 1. In drawing a wire having a wire diameter of 4.5 to 5.5 mmφ that has undergone a pickling process using a plurality of dies without going through an annealing and plating process, the dies at the initial stage of wire drawing. A wire drawing lubricant containing 3 to 15% of molybdenum disulfide or boron nitride is used as a lubricant in the process, and an oil-based lubricant containing a power supply improver and an arc stabilizer is used as a lubricant in at least the final die. In the final die, the wire is drawn under conditions such that the area reduction rate is 2 to 12%, and the power supply improver and arc stabilizer remaining on the surface of the wire product are in the range of 50 to 300 ppm and 10 to 300 ppm, respectively. A method for producing solid wire for welding, which consists of a continuous process of rewinding.