JPH08155674A - Small-diameter steel wire for arc welding - Google Patents

Abstract

PURPOSE: To provide a small-diameter steel wire for arc welding having good feedability, such as absence of slip at feed rollers and low friction resistance, even when the steel wire is welded under a high-current condition by using a long-sized soft conduit cable. CONSTITUTION: The wire having a lubricant consisting of a lubricating agent contg. one or two kinds of molybdenum disulfide and tungsten disulfide at 3 to 30wt.%, one or >=2 kinds of a fatty acid of a m.p. of >=50 deg.C, ester of monovalent or bivalent alcohol of the fatty acid and petroleum wax at 20 to 60wt.% and metal soap at 5 to 20wt.% and consisting of the balance liquid at ordinary temp. on the surface of the steel wire for arc welding at 0.20 to 1.80g per 10kg the wire is formed.

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 is inevitably high. In addition, depending on the target structure, welding is often performed in the squeezed part, 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 is used. Bends to make it easier to use, so it tends to be soft and long. In this way, the supply speed of the welding steel wire increases, and when it is used in a long and bendable conduit cable, the friction resistance increases when the wire passes through the conduit tube inside the conduit cable during wire feeding. However, there is a problem in that the wire feeding during welding is hindered and the arc becomes unstable and welding cannot be performed.

For this reason, various measures have been taken so far for the small diameter steel wire for welding in order to improve the wire feeding property, but there are still no sufficient measures, and the welding operator is harsh. We are often forced to interrupt welding under certain conditions, and we have difficulty dealing with such things as replacing worn conduit tubes. To solve the problem of feedability of the small diameter steel wire for welding, for example, an ester composed of a higher fatty acid and a higher monohydric alcohol and the ester, MoS ₂ and graphite have been hitherto disclosed in JP-A-55-40068. Steel wire for arc welding mixedly coated with the like, or JP-A-58-
Japanese Patent No. 184095 proposes a steel wire for arc welding in which a mixture of solid lubricants such as graphite, molybdenum disulfide and glass powder is applied to the surface of the steel wire.

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 the 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.

[0005]

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.

[0006]

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
20 to 60 wt% of one kind or two or more kinds, 5 to 20 wt% of one or more kinds of metal soap, and the balance of 0.20 to 1. It is a small diameter steel wire for arc welding characterized by having 80 g.

[0007]

[Function] On the surface of a steel wire for arc welding, one or two kinds of molybdenum disulfide and tungsten disulfide, a fatty acid having a high melting point, an ester of a monohydric or dihydric alcohol of a fatty acid, and one or more species of petroleum wax. By using an appropriate amount of one or more metal soaps and a liquid lubricant, the feeding roller does not slip even under severe conduit cable use or high current conditions, and the friction resistance is low, so wire feeding Feedability is extremely 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 type or two types 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 of the fatty acid or 2 in the conduit tube becomes hot when the welding is performed for a long time due to the frictional heat of the wire and the heat of 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. . Further, if these are 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, peeling and accumulation in the conduit tube is large, and it accumulates and the feed resistance is large. Also, the wire feed roller part slips and feeds the wire. Unevenness occurs, wire feedability becomes poor, and the arc becomes unstable.

The fatty acids referred to in the present application are those having a melting point of 50 ° C. or higher, such as myristic acid, palmitic acid, stearic acid and melissic acid, and monohydric or dihydric alcohol esters of fatty acids are beeswax and carnauba wax. , Waxes such as cotton wax and synthetic waxes of higher fatty acids, and those having a melting point of 50 ° C. or higher. 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 one or more metal soaps
Must be These are water-soluble while 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 metal soap content is less than 5%, a large amount of water-insoluble components adhere to the wire, which accumulates lubricant in the feed roller part and conduit cable, causing the wire to slip at the feed roller part and the conduit cable. The internal frictional resistance becomes large and the arc becomes unstable. If the metal soap content exceeds 20%, the amount of spatter generated increases. The metallic soap means potassium soap, sodium soap, calcium soap and the like.

Further, one or two of molybdenum disulfide and tungsten disulfide on the surface of the steel wire for arc welding.
, One or more of fatty acids having a high melting point, 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.

[0012]

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 steel wire for arc welding, fatty acid, 1 of fatty acid
Wire diameter with various amounts of polyhydric or dihydric alcohol ester, petroleum wax, metal soap and liquid lubricant
~ 1.6 mm YGW1 specified in JISZ3312
No. 1 solid wire and a YFW-C50DR seamless flux-cored wire (flux filling rate 14%) specified in JIS Z3313 were prototyped. The apparatus shown in FIG. 1 was used to investigate the wire feedability. That is, for the purpose of increasing the feeding resistance, a wire pulled out from the spool 2 is fed by a feeding motor 3 to a 6 m conduit cable 1 provided with a loop 2 rotation of a diameter of 150 mm and fed to a torch 4, and each 10 kg of wire is fed. Welded. The welding conditions at that time are as shown in Table 1.

[0013]

[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.

[0015]

[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.
No. 8 has a low melting point for fatty acids, esters of monohydric or dihydric alcohols of fatty acids, and lanolin, which is one of petroleum waxes, and therefore has a test No. Test No. 10 had a small amount of fatty acids, esters of fatty acid monohydric or dihydric alcohols, and petroleum wax, and was also tested as Test 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 N
o. In No. 11, since the amount of metal soap was large, the amount of spatter generated was large. Test No. In No. 12, since the amount of metal soap 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.

[0018]

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.
20 to 60 wt% of one or two or more fatty acids having a melting point of 50 ° C. or higher, monohydric or dihydric alcohol esters of fatty acids and petroleum waxes, and 5 to 20 wt% of one or more metallic soaps %, And the balance contains 0.20 to 1.80 g of a lubricant consisting of a lubricant that is liquid at room temperature per 10 kg of wire.