JPH0971792A - Thin steel wire for arc welding - Google Patents

Abstract

(57) [Abstract] [Problem] To use a soft and long conduit cable,
Further, it is an object of the present invention to provide a thin steel wire for arc welding, which has a good feedability such as no slip at the feed roller and a small frictional resistance even when it is welded under a high current condition. SOLUTION: One type or two types of molybdenum disulfide and tungsten disulfide are applied to the surface of a steel wire for arc welding.
˜30 wt%, fatty acid having a melting point of 50 ° C. or higher, ester of fatty acid monohydric or dihydric alcohol and 20 to 60 wt% of one or more petroleum waxes, 5 to 20 wt% of polyethylene glycol, and the rest liquid at room temperature The lubricant consisting of the lubricant is 0.20 per 10 kg of wire
It is characterized by having ˜1.80 g.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steel wire for arc welding, and more particularly to a small diameter steel wire for arc welding which is excellent in feedability during welding.

[0002]

2. Description of the Related Art Small-diameter steel wire for arc welding tends to be used more and more with the progress of automation and higher efficiency of welding, but recently, from the point of efficiency, high current can be used for both automatic and semi-automatic welding. Welding conditions are being adopted. As a result, the wire feeding speed inevitably increases. In addition, depending on the target structure, welding is often performed in narrow spaces, and from the viewpoint of ease of use at those locations, the conduit cable from the feed roller of the wire feeder of the welding machine to the welding torch. Bends to make it easier to use, so it tends to be soft and long.

As described above, when the welding steel wire is supplied at a high speed and is used in a long and easily bendable conduit cable, friction resistance occurs when the wire passes through a conduit tube in the conduit cable during wire feeding. Becomes large, which hinders the wire feeding during welding, and the arc becomes unstable, resulting in the problem that welding cannot be performed. For this reason, the small diameter steel wire for welding has been
Various measures have been taken to improve the wire feedability, but none are sufficient, and welding workers are often forced to interrupt welding under severe conditions, such as replacing worn conduit tubes. , I'm having a hard time responding.

Regarding the problem of the feedability of the small diameter steel wire for welding, there has been hitherto been known, for example, in JP-A-55-40068.
Japanese Patent Laid-Open No. 58-184095 discloses a steel wire for arc welding in which an ester composed of a higher fatty acid and a higher monohydric alcohol and a mixed coating of the ester and MoS ₂ , graphite, or the like, or graphite or disulfide described in JP-A-58-184095. A steel wire for arc welding in which a mixture of a solid lubricant such as molybdenum or glass powder is applied to the surface of the steel wire has been proposed.

However, also in these steel wires for arc welding, under the severe condition that the above-mentioned soft and long conduit cable is used and welding is performed under high current condition, the wire is fed in the feeding roller portion. Slip or frictional resistance in the conduit tube is large, and the inside of the conduit tube becomes hot due to frictional heat and heat generated by the welding cable wrapping the conduit liner, and the lubricant on the wire surface partially melts and aggregates on the wire surface. The feedability was not satisfactory because the lubricant was not evenly covered.

[0006]

SUMMARY OF THE INVENTION Therefore, according to the present invention, even when a soft and long conduit cable is used and welding is performed under a high current condition, the feeding roller has no slip and a friction resistance is reduced. It is an object of the present invention to provide a small diameter steel wire for arc welding having a small feedability.

[0007]

That is, the gist of the present invention is that one or two kinds of molybdenum disulfide and tungsten disulfide are present on the surface of a steel wire for arc welding in an amount of 3 to 30 wt% and a melting point of 50 ° C. or higher. Fatty acids, 1 of fatty acids
Of dihydric or dihydric alcohols and petroleum wax 1
0.2 to 10 wt% of the wire, or 20 to 60 wt% of the two or more types, 5 to 20 wt% of polyethylene glycol, and the balance is a liquid lubricant at room temperature.
It is characterized by having 0 to 1.80 g.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION One or two kinds of molybdenum disulfide and tungsten disulfide, a fatty acid having a high melting point, a monohydric or dihydric alcohol ester of fatty acid and one kind of petroleum wax on the surface of a steel wire for arc welding. Alternatively, by using two or more kinds of polyethylene glycol and a liquid lubricant in appropriate amounts, there is no slip at the feeding roller and friction resistance is small even under severe conduit cable use and high current conditions, so wire feeding performance is improved. Very good. These effects can be achieved by the coexistence effect and the synergistic effect of each composition. The reasons for limiting each composition will be described below.

First, one kind or two kinds of molybdenum disulfide and tungsten disulfide are 3 to 30 wt%. If the amount of one or two of molybdenum disulfide and tungsten disulfide is less than 3 wt%, the frictional resistance in the conduit tube becomes large, and the wire feedability becomes poor. On the other hand, when it exceeds 30 wt%, the wire slips at the wire feeding roller portion and the feeding becomes uneven so that the arc becomes unstable.

The fatty acid having a melting point of 50 ° C. or higher, the ester of a monohydric or dihydric alcohol of the fatty acid, and one or more petroleum waxes must be 20 to 60 wt%.
These are water repellent and have an anticorrosive effect. Further, since it is solid, molybdenum disulfide and tungsten disulfide can be uniformly held. When the melting point is less than 50 ° C., the fatty acid, the monovalent fatty acid or 2 of the fatty acid is heated in the conduit tube when the welding is performed for a long time due to the frictional heat of the wire and the heat generated by the welding cable wrapping the conduit liner.
Esters of polyhydric alcohol and petroleum wax melt on the wire surface and partially agglomerate, and the lubricant on the wire surface is not uniform, and the friction resistance in the conduit tube increases, resulting in poor wire feedability. .

If the content of these elements is less than 20% by weight, the adhesion of molybdenum disulfide and tungsten disulfide deteriorates. Therefore, the frictional resistance in the conduit tube becomes large, and the wire feedability becomes poor. On the other hand, if it exceeds 60 wt%, the amount of lubricant on the wire surface is large and peeling and accumulation in the conduit tube is large, which accumulates and the feed resistance is large, and the wire feed roller part slips and feeds the wire. Unevenness occurs, wire feedability becomes poor, and the arc becomes unstable.

The fatty acid referred to in the present invention is one having a melting point of 50 ° C. or higher, such as myristic acid, palmitic acid, stearic acid, and melissic acid, and a monohydric or dihydric alcohol ester of fatty acid is beeswax, carnauba. A wax having a melting point of 50 ° C. or higher, such as wax, cotton wax, and synthetic wax of higher fatty acid. Petroleum wax refers to those having a melting point of 50 ° C. or higher obtained by refining petroleum, such as solid paraffin and betrolatum.

5 to 20 wt% of polyethylene glycol
Needs to be These are water-soluble, whereas fatty acids, esters of monohydric or dihydric alcohols of fatty acids and petroleum waxes are water-insoluble.
The ester of dihydric or dihydric alcohol and petroleum wax are firmly adhered to the wire surface to prevent peeling in the feeding roller and the conduit tube. If the content of polyethylene glycol is less than 5%, a large amount of water-insoluble component adheres to the wire, which accumulates lubricant in the feed roller and conduit cable, causing the wire to slip at the feed roller and the conduit cable. The internal frictional resistance becomes large and the arc becomes unstable. If polyethylene glycol exceeds 20%, the amount of spatter generated increases. There are various molecular weight polyethylene glycols,
In the present invention, those having an average molecular weight of 2000 or more are preferable.

Further, one or two of molybdenum disulfide and tungsten disulfide on the surface of the steel wire for arc welding.
One or more of species, fatty acids having a high melting point, esters of monohydric or dihydric alcohols of fatty acids, and petroleum waxes,
The amount of one or more metal soaps and the liquid lubricant should be 0.20 to 1.80 g per 10 kg of wire. If it is less than 0.20 g, the friction resistance in the conduit tube becomes large and the wire feedability becomes poor.
If it exceeds 0 g, the wire slips at the wire feeding roller portion and uneven feeding occurs, and the arc becomes unstable. The small-diameter steel wire for arc welding of the present invention is a solid wire such as Si-Mn system or Si-Mn-Ti system defined in JIS Z3312, or a flux cored wire defined in JIS Z3313, and has a diameter of 0.8. It is a thin wire of about 2.0 mm.

[0015]

The present invention will be described in more detail with reference to the following examples. First, molybdenum disulfide and tungsten disulfide on the surface of the steel wire for arc welding, fatty acid, 1 of fatty acid
YGW11 solid wire and JIS Z defined in JIS Z3312 with a wire diameter of 1.2 to 1.6 mm in which the amounts of polyhydric or dihydric alcohol ester, petroleum wax, polyethylene glycol and liquid lubricant are variously changed.
A YFW24 seamless flux-cored wire (flux filling rate of 15%) specified in 3313 was prototyped.
The apparatus shown in FIG. 1 was used for the investigation of the wire feedability. That is, the loop 2 with a diameter of 150 mm is used to increase the feeding resistance.
Spool 2 on 6m conduit cable 1 with rotation
The wire pulled out from the wire was fed by the feed motor 3 and fed to the torch 4, and 10 kg of each wire was welded. Table 1 shows the welding conditions at that time.

[0016]

[Table 1]

The wire feedability was examined by measuring the armature current of the feed motor 3. Regarding the wire feedability, when the armature current exceeds 3.5 A, the protruding length of the wire changes and the arc becomes unstable. The slip of the wire in the wire feeding roller portion was investigated by measuring the peripheral speed of the feeding roller and the wire speed at the outlet side of the feeding roller, and calculating the slip ratio by the following formula. When the slip ratio of the wire exceeds 5%, the wire feeding speed becomes slower and the wire is unevenly fed so that the arc becomes unstable and the amount of spatter is increased. Slip rate = (peripheral speed of feed roller) − (wire speed at exit of feed roller) / (peripheral speed of feed roller) × 100 The results are summarized in Table 2.

[0018]

[Table 2]

In Table 2, the test No. 1 to 5 are small-diameter steel wires for arc welding according to the present invention, Test No. 6 to 14 are comparative examples. Test No. of the present invention example. In Nos. 1 to 5, the slip ratio during welding and the armature current of the feed motor were low, the arc was stable, and the results were extremely satisfactory. Test No. in the comparative example. In Test No. 6, the total amount of molybdenum disulfide and tungsten disulfide was large, and Test No. 6 was used. 9 is a fatty acid,
The total amount of monohydric or dihydric alcohol ester of fatty acid and petroleum wax was large, and the test No. In No. 13, since the lubricant content per 10 kg of wire was large, the slip ratio became high during welding and the arc was unstable.

Test No. Test No. 7 has a small total amount of molybdenum disulfide and tungsten disulfide, and therefore, Test No.
Test No. 8 has a low melting point for fatty acids, monohydric or dihydric alcohol esters of fatty acids, and lanolin, which is one of petroleum waxes. Test No. 10 had a small amount of fatty acid, ester of fatty acid monohydric alcohol or dihydric alcohol, and petroleum wax, and was also tested No. 10. Since No. 14 had a low lubricant content per 10 kg of wire, the friction resistance of the wire increased in the conduit tube, the armature current of the feed motor increased, and the arc was unstable.

Test No. In No. 11, since the amount of polyethylene glycol was large, the amount of spatter generated was large. Test N
o. In No. 12, since the amount of polyethylene glycol was small, the slip ratio increased during welding, the frictional resistance of the wire in the conduit tube increased, the armature current of the feed motor also increased, and the arc was unstable.

[0022]

As described in detail above, according to the thin steel wire for arc welding of the present invention, even when a soft and long conduit cable is used and welding is performed under high current conditions, The feed roller has no slip, and the frictional resistance is small, so that the feedability is good and stable arc welding is possible.

[Brief description of drawings]

FIG. 1 is a diagram showing a welding device used in an embodiment of the present invention.

[Explanation of symbols]

 1 Conduit cable 2 Spool 3 Feed motor 4 Torch

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Claims (1)

[Claims] 1. A surface of an arc welding steel wire is coated with one or two of molybdenum disulfide and tungsten disulfide.
˜30 wt%, fatty acid having a melting point of 50 ° C. or higher, ester of fatty acid monohydric or dihydric alcohol and 20 to 60 wt% of one or more petroleum waxes, 5 to 20 wt% of polyethylene glycol, and the rest liquid at room temperature The lubricant consisting of the lubricant is 0.20 per 10 kg of wire
A thin steel wire for arc welding, which has a weight of ˜1.80 g.