JPS649920B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method of manufacturing a wire for arc welding, and more particularly to a method of manufacturing a flux-cored wire for arc welding with improved wire feedability. In general, arc welding wires are used automatically and semi-automatically in welding, and welding takes place for a long time.
Permanently stable feeding of the wire with small welding voltage fluctuations is required, and a wire surface with lubricity and a wire surface free from flaking to prevent the wire feeding path are required. The wire used as flux-cored wire for arc welding is a circular wire made by filling and encapsulating flux in a steel band, and is more complex in terms of manufacturing technology than copper-plated solid arc welding wire. be. An example of such a conventional manufacturing method for flux-cored wire for arc welding is that a steel strip is fed to a forming machine, where it is sequentially roll-formed into a predetermined shape, forming a circular wire. During this process, a predetermined amount of flux is filled into the wire using a powder feeder.
Next, in the wire drawing process of cold drawing, the wire is drawn using a fixed wire drawing die, but the wire is drawn under a high load, and unlike solid wire, flux-cored wire is hollow and difficult to draw. Because of its inferior properties, wire is drawn using a dry wire drawing lubricant (hereinafter referred to as "lubricant") composed of solid powder that must contain fatty acid salts, and is used as a strand of flux-cored wire for arc welding. . In order to use the drawn wire for welding,
As will be described later, the lubricant adhering to the wire surface peels off and accumulates in the wire feeding path, interfering with wire feeding. Therefore, fatty acid salts adhering to the wire surface acting as a binder are removed from the atmosphere by high-temperature heating. The lubricant is removed from the wire surface by combustion in the wire or by sublimation in a non-oxidizing atmosphere. However, the surface of the wire without lubricant has no lubricity and cannot be fed to the wire. Therefore, it is necessary to apply a liquid lubricant that does not flake or accumulate, or to cold draw and draw the wire for arc welding. It is a flux-cored wire. Here, we will estimate the state of lubricant adhesion on the wire surface during the conventional wire drawing process by cold drawing,
The wire feedability will be explained. First, the state of adhesion of the lubricant to the wire surface will be explained. Before wire drawing, the wire is drawn into a fixed wire drawing die with the lubricant adhering to the wire surface. There, the wire is reduced in area to the die diameter by a drawing force. The lubricant, which is a solid powder, is sandwiched between the introduction surface of the die and the wire surface, and is first subjected to a strong crushing action by the wire surface while being compressed. Next, the fatty acid salt in the lubricant spreads and melts on the die surface where it will be crimped, and acts as a binder that bonds the gaps between the lubricant particles or the wire surface, creating a strong bond to the wire surface. Forms a pressure-adhesive film. The fatty acid salts that have not yet melted remain as solid particles, and together with other solid particles they act as rollers, helping to lubricate the surface of the wire and the inner surface of the die as the wire passes through the die. However, when the solid particles acting as rollers that could not be pressed into tight contact with the wire surface are released from the crimped state, the compressed air between the particles expands, and the particles simply adhere to the wire surface. This makes it easy to peel off. Next, to explain the wire feeding performance, wire feeding during welding is carried out at the welding machine and its terminal from feeding rollers each having a circular internal feeding path to a long, winding conduit cable in a straight line. The wire is fed by forced extrusion to the welding chip, and the wire is fed while the surface of the wire is constantly in contact with the wall of the circular internal feeding path, even if it is bent. In other words, in the case of a wire surface that has a lubricant attached to it that easily peels off, the wire surface comes into contact with the inner wall of the feed path even if it is bent, so the lubricant that easily peels off easily and gradually If welded for a long time, it will accumulate and block the feed path, preventing the wire from being fed. In other words, as described above, the lubricant that is merely adhered to the surface of the wire in the wire drawing process without being press-fitted easily peels off and accumulates in the wire feeding path. On the other hand, a wire surface that does not have any lubricant has the disadvantage that the contact resistance becomes too large in the wire feeding path, making it impossible to smoothly feed the wire. In addition, polishing and stripping using only forced means also has the disadvantage that the stripped lubricant cannot be completely removed, so it re-adheres, and the flaked lubricant accumulates in the wire feed path, preventing the wire from being fed. . The object of the present invention is to eliminate the above-mentioned drawbacks of the prior art.The purpose of the present invention is to polish and clean the drawn wire so that no material is peeled off during wire feeding, and then use the wire to draw the wire after it is tightly compressed. The lubricant is left behind and the lubricity of the remaining lubricant is utilized to improve wire feeding performance. In other words, the gist is that the wire is drawn by cold drawing using a powdered lubricant containing sodium stearate or calcium stearate at a weight ratio of 10% or more, and then the wire surface is polished to reduce the boiling point to 150°C or less and the viscosity. By washing with an organic solvent of 0.9CP (20℃) or less and subsequently drying at a temperature of 150℃ or less, 0.005 to 1.0g of the powder lubricant used in the wire drawing process remains per 10kg of wire weight. A method for manufacturing an arc welding wire, characterized by: It is in. The present invention prevents the lubricant from peeling off from the wire surface without completely removing the adhesion of the lubricant to the wire surface during the wire drawing process, which has been considered a problem in the past, and improves the good lubricity of the lubricant on the wire surface. This dramatically improves wire feedability during welding. That is, the present invention polishes off the lubricant adhering to the surface of the wire, which is easily peeled off, performs cleaning to prevent re-adhesion, forms a strong film on the wire surface, and creates a lubricant that is pressure-bonded. In order to make use of the good lubricity of the lubricant on the circular inner wall, the wire is dried at a drying temperature that does not cause deterioration of the wire and lubricant, so that no cleaning liquid remains, and the wire feedability is improved. It is ivy. The composition of the dry wire drawing lubricant used in carrying out the present invention may be any known dry wire drawing lubricant applied to steel wire drawing, except that it contains sodium stearate or calcium stearate as a fatty acid salt in an appropriate amount as described below. Any wire drawing lubricant may be used, and the particle size of the powder may be any known particle size. Further, the wire surface may be polished to remove the lubricant by simply rubbing the wire surface, and any known method using a wire brush, sand, etc. may be used. The scope of the present invention will be explained below. Sodium stearate or calcium stearate, which belong to the fatty acid salts in the dry wire drawing lubricant, cause less wear on wire drawing dies during the cold drawing wire drawing process, and do not affect weldability during welding. If the content of sodium or calcium stearate contained in the present lubricant is 10% by weight or more, the wire may , No exfoliation occurs during wire feeding, and wire feeding performance is good. If the stearate content is less than 10% by weight, the lubricant on the wire surface will be easily stripped off, and after polishing, stripping and cleaning, the lubricant will be difficult to remain on the wire surface, which will reduce the lubricity of the wire surface. is damaged, and wire feedability is reduced. The solution used to clean the lubricant that has peeled off from the wire surface should be one that can prevent the lubricant from re-adhering and that can be easily dried. However, due to work and wire quality considerations, the drying temperature The boiling point is below 150℃ and the viscosity is 0.9CP (at20
An organic solution with a temperature below ℃) is optimal, and does not generate exfoliated materials when feeding the wire, improving wire feeding performance. If the boiling point of the organic solution is over 150°C, a drying temperature of over 150°C is required to prevent the solution from remaining on the wire, which may cause the fatty acid salt to soften and the wire to oxidize if dried in the air. Wire feeding performance deteriorates. In addition, if the viscosity exceeds 0.9CP (20℃), the solution will form a thick film on the wire surface after cleaning the wire, and the peeled lubricant may remain in the film thickness, which may cause problems in wire feeding. Exfoliation occurs. Note that if water other than an organic solution or an inorganic aqueous solution is used, perhaps because of its high viscosity, exfoliation occurs during wire feeding, and the wire feeding performance deteriorates. In the present invention, the dry wire drawing lubricant remains,
This improves the wire feedability of arc welding wire. If the amount of lubricant remaining on the wire surface of the arc welding wire manufactured within the scope of the present invention is 0.005 to 1.0 g per 10 kg of wire weight, no exfoliation will occur in the wire feeding path. ,
Improves wire feedability. Moreover, if it is less than 0.005 g, the wire feeding stability will be lost, probably due to insufficient lubricity on the wire surface, and the wire feeding performance will deteriorate. On the other hand, if it exceeds 1.0 g, perhaps due to insufficient peeling of the lubricant to the wire surface, exfoliated matter will occur and accumulate in the wire feeding path, impeding wire feeding and deteriorating wire feeding performance. Next, as an example of the present invention, an example of manufacturing a flux-cored wire for carbon dioxide gas arc welding with a diameter of 1.6 mm is shown in Tables 1 and 2. The wire is a JIS standard steel strip with a thickness of 0.9mm and a width of 13mm.
The wire is then slit into a shape, and the wire is shaped with a forming roller from a U-shape to a simple O-shape in cross section. On the way, the U-shaped groove is filled with a flux whose main component is titanium oxide at 15% of the weight of the wire. Diameter 2.2mm
A strand of wire for wire drawing is created. The wire was drawn using seven JIS/W104 type dies with an area reduction rate of less than 20%, and the final wire drawing speed was 900 to a diameter of 1.6 mm.
m/min. Furthermore, the wire that has been drawn is wound over a total length of 50 cm using a fixed metal scrubber, and the entire surface of the metal scrubber is continuously sprinkled with cleaning liquid at a rate of 5/min. Then,
The wire surface was polished, cleaned, and then dried under air heat for 10 minutes. Under the above-mentioned wire manufacturing conditions, the types of dry wire drawing lubricants shown in Table 1 used during wire drawing were provided in front of each die and filled in the box through which the wire was passed. Further, although the type of cleaning liquid and drying temperature are shown in Table 1, the cleaning liquid was overcirculated. Table 1 also shows the boiling point and viscosity at 20°C of the cleaning liquid used within the scope of the present invention. Such wire tests include determining the amount of dry wire drawing lubricant applied to a 10kg wire, and determining the stability of wire feeding based on the range of change in welding voltage when 10kg of wire is continuously automatically welded using a DC welding machine. The presence or absence of exfoliated materials was investigated in the conduit cable, which is the wire feed path from the welding machine, to determine the wire feedability. The results are shown in Table 2. The welding conditions in this test were: carbon dioxide flow rate 20/min, voltage 30V, current 350Amp, and welding speed.
300mm/min, the conduit cable is 3m long,
It is made into a loop with a diameter of 400mm.

【table】

【table】

[Table] No. 1 wire is outside the scope of the present invention because it is still drawn, and the amount of lubricant remaining on the wire surface is also outside the scope of the present invention, resulting in lack of stability in wire feeding or failure. There is also the generation of debris, and the wire feeding performance is poor. For No. 2 wire, the cleaning liquid was water, which is outside the scope of the present invention, and the amount of lubricant remaining on the wire surface is also outside the scope of the present invention, and the wire feeding stability is lacking or there may be flaking of the wire. Feeding performance is poor. The viscosity of the No. 3 wire is a type of cleaning liquid that is outside the range of the present invention, and the amount of lubricant remaining on the wire surface is also outside the range of the present invention, and although the wire feeding is stable, there is the occurrence of exfoliation. Wire feeding performance is poor. Wire No. 4 was outside the range of the present invention at a drying temperature and did not cause any flaking, but lacked stability in wire feeding and had poor wire feeding performance. Wire No. 5 has a content of calcium stearate that is outside the scope of the present invention among the types of dry wire drawing lubricants, lacks stability in wire feeding, and may cause flaking, resulting in poor wire feeding performance. No. 6 wire is an example within the scope of the present invention in terms of the wire drawing dry lubricant type, cleaning liquid type, drying temperature, and amount of lubricant remaining on the wire surface, and has stable wire feeding and no peeling. There was no occurrence of anything,
Excellent wire feedability. Like the No. 6 wire, the No. 7 wire is an example within the scope of the present invention, and has stable wire feeding, no peeling material, and excellent wire feeding performance. The No. 8 wire, like the No. 6 and No. 7 wires, is an example within the scope of the present invention, and has stable wire feeding, no peeling material, and excellent wire feeding performance. Although the present invention has been described above mainly in relation to the production of flux-cored wire for arc welding, the present invention is of course not limited to this, and does not depart from the scope thereof unless it is contrary to the purpose of the present invention. From this point of view, the dry drawing lubricant adhering to the wire surface of the dry drawn arc welding wire is re-treated with lubricant without completely removing it to improve wire feedability. Rather than improving the wire drawing lubricant, we utilize the lubricity of the remaining dry wire drawing lubricant.
The present invention, which improves wire feedability, has great industrial value.

Claims (1)

[Claims] 1. Wire drawing is performed by cold drawing using a powder lubricant containing at least 10% by weight of sodium stearate or calcium stearate, and then the wire surface is polished to achieve a boiling point of 150°C or less and a viscosity of 0.9CP (20
By washing with an organic solvent below 150°C and drying at a temperature below 150°C, the powder lubricant used in the wire drawing process is reduced to 0.005 to 0.005% per 10 kg of wire weight.
A method for producing arc welding wire, characterized in that 1.0g remains.