JP2003305587A - Wire for gas-shielded arc welding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wire for gas-shielded arc welding, which shows excellent wire-feeding property without running out of lubricant even if used in such a severe environment that wire bending or the like makes feed resistance higher. <P>SOLUTION: The wire for gas-shielded arc welding has a phosphate film of 0.05-0.6 μm on its wire surface. Regarding its surface roughness, a load length ratio tp[L/Cv=30%] is 40-90% and an arithmetic average roughness Ra[L] is 0.05-0.20 μm. An adhered amount of the feed lubricant on the wire surface is 0.1-4.0 g per 10 kg wire. Regarding the color tone of the wire surface, the L value of lightness is 40-60 and the C value of chroma is 1-10. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flux-cored wire for fully automatic and semi-automatic welding, which is excellent in wire feeding property,
The present invention relates to a wire for gas shielded arc welding such as a solid wire.

[0002]

2. Description of the Related Art Generally, CO ₂ gas shielded arc welding,
A gas shielded arc welding wire having a small diameter (0.8 to 1.6 mm) is used for MIG welding or the like. The wire for gas shielded arc welding is wound on a spool or loaded in a pail pack for welding. When using this wire for gas shielded arc welding, pull out the wire from the spool or pail pack by the feeding roller of the feeder and push it into the liner enclosed in the subsequent conduit cable, and through this liner, the conduit The method of feeding to the power feed tip inside the welding torch attached to the tip of the cable is adopted. The wire is subjected to arc welding by applying a voltage between the power feed tip and the material to be welded.

The liner used here is a flexible guide tube formed by spirally forming a steel wire, and its length is usually about 3 to 6 m, but it is 10 to 20 m when welding a wide area. It becomes long and is selected and used according to the distance to the welding point. According to this method, there is an advantage that welding can be performed relatively easily by running the conduit cable (liner) even if the welding site such as a shipbuilding site is narrow or has a height difference.

However, the following problems may occur during use, and it is required to solve them. In order to carry out stable welding, it is necessary to supply the gas shielded arc welding wire to the welded portion at a predetermined constant rate, that is, to have good wire feedability. The wire is pushed into the liner by the feeding force of the feeding roller, while the liner inner surface receives a feeding resistance due to contact friction. At this time, when the liner is in a relatively gentle usage environment that is almost straight, the feed resistance is not so large and there is no problem in feedability, but there are many bending points and the bending radius (curvature radius) is small. In a severe operating environment such as when the liner becomes long, the feeding resistance increases, the balance with the feeding force is lost, and the wire feeding property deteriorates.

The surface condition of the wire has a great influence on the quality of the wire feeding property. That is, when the feeding resistance increases, if the amount of lubricant on the wire surface is small, the feeding speed becomes unstable and the wire feeding property deteriorates. Further, the wire is buckled in the liner, the surface of the wire is scraped by the feeding roller, and the scraps enter and accumulate in the liner, so that the feeding resistance is further increased. On the other hand, if the amount of lubricant on the surface of the wire is large, the feeding roller will slip excessively, and the wire will not be able to maintain a predetermined feeding speed, and the wire feeding performance will deteriorate. As a result, problems such as destabilization of the welding arc, uneven bead shape, defective fusion, and undercut occur.

Since there are few welding sites where the conduit cable is used in a straight line, it is common to weld the work while bending the conduit cable in a complicated and complicated place. There has been a strong demand for a wire for gas shielded arc welding that has good feedability. Conventionally, in order to secure the wire feedability, various lubrication treatments have been performed on the surface of the wire for gas shielded arc welding. For example, Japanese Patent Publication Sho 51-30
Japanese Patent No. 851 discloses a steel welding electrode wire having a phosphate coating formed on its surface. However, sufficient wire feedability cannot be ensured only by forming a phosphate film on the surface.

Further, Japanese Patent Publication No. 50-3256 discloses that
A gas shielded arc welding wire having a dense and smooth surface coated with lubricating oil is disclosed. However, if the wire surface is dense and smooth, it is difficult to apply a predetermined amount of lubricating oil evenly and stably, and in order to obtain a wire with good feedability, there is no choice but to apply a large amount of lubricating oil. Absent. However, the wire with a lot of lubricating oil on the wire surface is
Due to the increase of the feeding resistance, the feeding roller is likely to slip and it is difficult to cope with the curve of the liner, and further, the workability is poor and the material of the weld metal is deteriorated due to the increase of diffusible hydrogen. There is.

On the other hand, as an example of using a solid lubricant, Japanese Unexamined Patent Publication No. 50-146541 discloses that a main component is a mixture of molybdenum disulfide powder and graphite powder, or a mixture thereof and one or more flux components. A method for manufacturing a composite wire for welding, which is drawn by a wire drawing agent, is disclosed. Further, in JP-A-58-135795, as a wire for gas shielded arc welding, only one or both of graphite and molybdenum disulfide and a mixture of 10 to 60% by weight of glass powder are applied to the surface of the wire. And the amount of the lubricant is 5 × 10 of the wire weight.
^A gas shielded arc welding wire of ^{-2 to} 5 x 10 ^-4 % is disclosed. However, with the above technique, it is difficult to control the amount of lubricant adhered, and there are problems that excessive lubricant adheres to the area and that the lubricant adheres unevenly after wire drawing. Excessive lubricant buildup can lead to blockages in the conduit cable, making wire feeding difficult. Further, if the lubricant is unevenly attached, it becomes difficult to stably feed the wire.

Therefore, a technique has been proposed in which the roughness of the surface of the wire is increased and the lubricating oil is retained in the recesses so that the lubricating oil can be applied stably and evenly in the longitudinal direction of the wire. For example, in Japanese Examined Patent Publication No. 4-52197, wire drawing is performed after annealing in a specific gas atmosphere, and in Japanese Examined Patent Publication No. 58-56677, a hole die is used to forcibly lubricate by increasing lubricating oil pressure. A manufacturing technique for increasing the roughness of the wire surface by drawing is disclosed. However, the one disclosed in Japanese Patent Publication No. 4-52197 is a lateral groove extending in the circumferential direction of the wire and is effective as an oil reservoir but is not suitable as a solid lubricant reservoir.
In Japanese Patent Publication No. 58-56677, the flatness of the wire surface can be made small, but the roughness in the depth direction is difficult to obtain. Therefore, if the amount of lubricating oil adhered to the surface is not large, improvement in wire feedability is expected. Absent.

[0010]

SUMMARY OF THE INVENTION Therefore, according to the present invention, it is possible to exhibit good wire feedability without causing lubrication failure even in a harsh operating environment in which the feed resistance increases due to the bending of the liner or the like. An object of the present invention is to provide a gas shielded arc welding wire that can be manufactured.

[0011]

The gist of the present invention is that a wire for gas shielded arc welding has a phosphate coating of 0.05 to 0.6 μm on the wire surface,
Wire surface roughness is load length ratio tp [L / Cv = 30%]
40-90%, and calculated average roughness Ra [L] is 0.05-
It is characterized in that it is 0.20 μm, and the amount of the lubricant fed to the surface of the wire is 0.1 to 4.0 g per 10 kg of the wire. In addition, the lightness L value of the wire surface color tone is 40 to 6
0, and the saturation C value is 1 to 10.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.
In order for the wire for gas shielded arc welding to have good feed performance, the feed lubricant (solid lubricant, feed lubricant) effective for wire feedability must be uniform and stable in the wire longitudinal direction. It is necessary that they are attached, and for that purpose, it is necessary that the surface of the wire has a surface roughness (irregularities) as a lubricant reservoir. To this end, the present invention has a phosphate coating on the wire surface. The phosphate coating itself has excellent lubricating performance,
Since the wire feeding performance is high and it has a wear reducing effect, the feeding resistance due to the contact friction from the inner surface of the liner can be reduced, and the wire feeding property is improved.

Further, the presence of the phosphate film has the effect of strengthening the adhesion of the feed lubricant. Of course, it has a function of reducing the friction coefficient between the die and the wire during wire drawing. The amount of phosphate film on the wire surface is 0.0
5 to 0.6 μm. If it is less than 0.05 μm, the adhering feed lubricant is likely to fall off, there is no friction reducing effect, and improvement in wire feedability cannot be expected. On the other hand, if it exceeds 0.6 μm, although it has a friction reducing effect, it has a bad influence on welding workability such as an increase in spatter generation amount and fume generation amount. The phosphate as used in the present invention means iron phosphate, manganese phosphate, zinc phosphate and the like.

Further, the surface roughness in the wire longitudinal direction (L direction) defined by JIS B0601-1994 is defined as the load length ratio tp [cutting level Cv = 30%] (hereinafter, tp [L
/ Cv = 30]. ) And the arithmetic mean roughness Ra (hereinafter,
It is called Ra [L]. ) Specifies as follows. tp [L / Cv = 30] = 40 to 90% Ra [L] = 0.05 to 0.20 μm (measurement condition; cutoff value λ _c = 0.8 mm, reference length] = 0.80 mm, evaluation length is l _n = 4.00 mm) this tp [L / Cv = 30] and Ra [L] is used stylus-type roughness meter (needle point 5 [mu] m), 45 in the circumferential direction of the wire
It can be obtained as the average value of the measured values in the longitudinal direction (L direction) at the positions at 8 ° intervals.

Here, the load length ratio tp is expressed as a ratio (%) of the total cutting length obtained when the roughness curve is cut at the cutting level Cv (%) parallel to the average line to the reference length. To be done. FIG. 1 shows a bearing curve (hereinafter referred to as BC) in which the relationship between the cutting level Cv (%) from the maximum peak and the load length ratio tp (%) is graphed, and the illustrated BC example is the wire surface of the present invention example. With BC of Cleavage level Cv = 30%
It shows that the load length ratio tp at 78 is 78%.

The load length ratio tp is an index showing the roughness shape of the wire surface, and the reason for setting tp [L / Cv = 30] to 40 to 90% in the present invention is that it is less than 40%. (Recessed area) becomes too large, and the amount of feed lubricant (particularly solid lubricant) adhered tends to increase. On the contrary, when it exceeds 90%, the protrusion becomes too large and the amount of feed lubricant adhered becomes large. Because it tends to decrease. When the amount of the solid lubricant adhered increases, the feeding roller slips excessively, and the wire cannot maintain a predetermined feeding speed, which deteriorates the wire feeding property. In addition, the supply lubricant may drop off inside the liner, which may shorten the service life of the liner. On the contrary, when the amount of the feed lubricant adhered decreases, when the feed resistance increases, the feed rate becomes unstable and the wire feedability deteriorates. Further, the wire surface is scraped by the feeding roller, and the scraps enter and accumulate in the liner, and the feeding resistance further increases.

Next, the arithmetic average roughness Ra [L] is an index showing the depth of roughness, and Ra [L] is 0.05 in the present invention.
The reason for defining to 0.20 μm is that if it is less than 0.05 μm, the height difference of the uneven portion becomes small and the retaining function of the feed lubricant becomes poor, and conversely, if it exceeds 0.20 μm, This is because the height difference becomes large and the amount of feed lubricant tends to adhere. In the present invention, the wire surface is
[L / Cv = 30] = 40 to 90% and Ra [L] = 0.
The shape has a shape in which the unevenness balance is specified by a combination of 05 to 0.20 μm, and thereby an appropriate amount of the feed lubricant is stably attached. In this sense, as a more desirable roughness range, tp [L / Cv = 30] = 60 to 80% and Ra
A combination of surfaces of [L] = 0.10 to 0.15 μm is recommended.

In the present invention, the feed lubricant is attached to the surface of the gas shielded arc welding wire. The delivered lubricant referred to in the present invention refers to delivered lubricant and solid lubricant. These feed lubricants adhere to the wire surface to reduce the coefficient of friction between the inner wall of the liner and the wire, and suppress the increase in feed resistance, which improves the wire feedability of the wire for gas shielded arc welding. Secure. Adhesion amount of feed lubricant is 10kg wire
It is preferably 0.1 to 4.0 g (g / 10 kgW) per unit. If it is less than 0.1 g / 10 kgW, the effect of suppressing the increase in feeding resistance is not recognized, and improvement in wire feeding performance cannot be expected. On the other hand, when it exceeds 4.0 g / 10 kgW, it excessively adheres to the surface of the wire, and the feeding roller slips largely to make stable feeding difficult. Further, the inside of the liner is polluted, and the feeding failure due to the clogging of the lubricant occurs. In the case of lubricating oil to be fed, it decomposes due to the heat of dissolution to generate a large amount of hydrogen, so
Deterioration of the weld metal material due to an increase in the amount of diffusible hydrogen is likely to occur.

The feeding lubricating oil may be animal or vegetable oil, mineral oil or synthetic oil. Palm oil, rapeseed oil, castor oil, pork oil, beef oil, fish oil or the like can be used as the animal or vegetable oil, and machine oil, turbine oil, spindle oil or the like can be used as the mineral oil. As the synthetic oil, hydrocarbon type, ester type, polyglycol type, polyphenol type, silicone type, fluorocarbon type and the like can be used. In order to further improve the lubrication performance in the lubricating oil to be fed, various fatty acids and other oiliness agents and phosphorus, chlorine, and sulfur extreme pressure additives may be added. You may add the additive (antioxidant) for preventing. Here, the desirable amount of the supplied lubricating oil is 0.05 to 2.0 g.
(G / 10 kgW) is preferable. Of course, it has a function of reducing the friction coefficient between the die and the wire during wire drawing.

The solid lubricant is a solid lubricant containing one or two kinds of MoS ₂ and WS ₂ , and other components include polytetrafluoroethylene (hereinafter referred to as PTFE), graphite, dry lubricant and the like. To be The amount of solid lubricant adhered to the wire 1 is
It is preferable that the amount is 0.05 to 1.0 g (g / 10 kgW) per 0 kg. The amount of the lubricant fed can be measured by chemical analysis (toluene / ether extraction method).

Next, in the present invention, the surface color tone of the wire surface is defined by the lightness L of the surface color tone defined by JIS Z 8729.
The value and the saturation C value are defined as follows. Lightness L value 40-60 Saturation C value 1-10 Lightness L value of wire surface color tone is 40-60, Saturation C value is 1
By setting it in the range of 10 to 10, the wire feeding property becomes good. When the lightness L value of the wire surface color tone is less than 40 and the saturation C value is less than 1, the amount of lubricant fed is large and the feed roller slips excessively. Cannot be maintained, and the wire feedability deteriorates. Also,
When the lightness L value of the wire surface color tone exceeds 60 and the saturation C value exceeds 10, the amount of lubricant fed is small, the feed resistance increases, and the wire feed speed becomes unstable, resulting in wire feed. The salary becomes worse.

The lightness L value and the saturation C value of the wire surface color tone can be obtained by averaging the values obtained by measuring the outermost winding surface of the spool winding wire at eight substantially equal intervals. Further, the wire surface brightness L value and the saturation C value can be measured with a colorimeter. In the present invention, a CR-300 manufactured by Minolta and a measuring diameter of 8 mm were used. The present invention is applicable to any solid-state solid wire or flux-cored wire in which flux is included in the wire (type with or without seam).

[0023]

EXAMPLES The effects of the present invention will be specifically described below with reference to examples. Flux-cored wire with a wire diameter of 1.2 mm (JIS Z3313 YFW-C50DR, flux filling rate 14%) and solid wire (JIS Z331)
2YGW11) was prototyped and used as a spool wire. The wire feedability evaluation test was performed using the apparatus shown in FIG. In FIG. 2, the spool winding welding wire 2 set in the feeder 1 is pulled out by the feeding roller 3 and fed to the welding torch 5 at its tip through the liner included in the conduit cable 4. Then, bead-on-plate welding was performed between the energizing tip and the steel plate 6.
The conduit cable 4 has a length of 6 m, and is provided with a curved portion 7 in which two loops having a diameter of 75 mm are formed in order to give a feeding resistance to the wire. The peripheral speed Vr of the feeding roller is set to the feeder 1.
(= Set wire speed) detector (not shown), wire actual speed (Vw) detector 8 are provided. The slip ratio S1 of the feedability evaluation index is S1 = (Vr−Vw) / Vr × 1
It is represented by 00%. Further, the reaction force received by the wire from the liner at the time of feeding by the load cell 9 provided in the feeding roller portion was detected as the feeding resistance R. Feeding resistance R is 6k
When the slip ratio S1 is 10% or less and gf or less, it is determined that the feedability is good. In the wire feedability test, welding was performed for 20 minutes under the welding conditions shown in Table 1, the feed resistance R and the slip ratio S1 were measured, and the average value was obtained. The results are shown in Table 2.

[0024]

[Table 1]

[0025]

[Table 2]

In Table 2, No. 1 to 7 are examples of the present invention, N
o. 8 to 15 are comparative examples. No. 1, which is an example of the present invention. 1
7 to 7, the amount of phosphate film on the wire surface, the load length ratio tp of the surface roughness and the calculated average roughness Ra are in the appropriate ranges,
In addition, the feed lubricant (solid lubricant, feed lubricating oil) also had an appropriate amount of adhesion, so both feed resistance and slip ratio were low, and good feedability was exhibited, and the arc was stable. N in Comparative Example
o. No. 8 had a small amount of phosphate film and was No. No. 10 has a low load length rate tp of wire surface roughness, and No. 12 is
The calculated average surface roughness Ra of the wire surface roughness is low.
o. In No. 14, since the amount of the fed lubricant was small and both the lightness L and the saturation C of the color tone were low, the wire feeding resistance R became high and the arc became unstable in any of the examples.

No. 9 has a large amount of phosphate film, so
The amount of spatter generated increased. No. No. 11 has a high load length ratio tp of wire surface roughness, and No. No. 13 has a high calculated average surface roughness Ra of the wire surface roughness. 1
In No. 5, since the amount of the fed lubricant was large and both the lightness L and the saturation C of the color tone were high, the slip ratio S1 was high in all cases, and the arc became unstable.

[0028]

As described above in detail, according to the gas shielded arc welding wire of the present invention, the lubrication failure occurs even in a harsh operating environment in which the feed resistance increases due to the bending of the liner or the like. It is possible to provide a wire for gas shielded arc welding capable of exhibiting excellent wire feedability.

[Brief description of drawings]

FIG. 1 is an example of a bearing curve of a wire of the present invention.

FIG. 2 is a diagram showing a wire feedability test apparatus used in an example of the present invention.

[Explanation of symbols]

1 feeder 2 Welding wire 3 feeding rollers 4 conduit cable 5 torch 6 steel plate 7 Conduit cable bend 8 wire speed detector 9 load cell

Claims (2)

[Claims] 1. A gas shielded arc welding wire having a phosphate coating of 0.05 to 0.6 μm on the wire surface, and the wire surface roughness having a load length ratio tp [L / Cv =
30%] is 40 to 90%, the calculated average roughness Ra [L] is 0.05 to 0.20 μm, and the amount of lubricant fed on the wire surface is 0.1 to 4.0 g per 10 kg of wire. A wire for gas shielded arc welding, which is characterized in that 2. The lightness L value of the wire surface color tone is 40 to 6.
The gas shielded arc welding wire according to claim 1, wherein the wire has a C value of 0 and a saturation C value of 1 to 10.