JPH11207492A - Manufacture of flux cored wire for welding stainless steel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a wire manufacturing cost and to make a wire quality stable by adding a prescribed amount of synthetic mica to the flux packed in the sheath and mixing them in the flux cored wire for welding stainless steel. SOLUTION: In a flux cored wire for welding stainless steel, when flux composed of a slag material and a metallic material, in a weight ratio to the total weight of the wire, is packed by 10-25% in the inside of the sheath made of stainless steel, synthetic mica of 0.05-0.20% to improve drawing workability is added to the flux to execute drawing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a flux-cored wire for gas shielded arc welding for stainless steel used in sluice gates and buildings, etc., which facilitates a reduction in the disconnection rate in the drawing process. In the figure, flux segregation in the wire was prevented.

[0002]

2. Description of the Related Art Conventionally, the production of a flux cored wire for welding stainless steel is generally performed by filling a flux using a shell substantially identical to a target metal component to be welded, and thereafter performing a wire drawing process. It is. At this time, since the work hardening of the outer stainless steel used during wire drawing is remarkable, troubles in production such as wire breakage may occur. In such a case, a method has been adopted in which the wire is annealed under appropriate conditions, the wire is softened, and the wire drawing is continued, but the flux filled during annealing is sintered inside the wire and drawn. It became difficult to collapse in the line direction, causing disconnection and flux segregation, which was a major obstacle. To prevent the segregation of the flux, it has been proposed in Japanese Patent Publication No. 6-37000 to specify the flux particle size and the particle diameter to prevent the segregation of the flux and the disconnection during the wire drawing.

[0003]

However, Japanese Patent Publication No. Hei 6-3
It is difficult to prevent the segregation of the flux only by adjusting the particle size distribution and the particle size of the flux as described in Japanese Patent Publication No. 7000, and the flux in the wire is being drawn. Therefore, the flux may become uneven in the wire, causing disconnection or segregation, which is not effective in improving productivity or stabilizing the quality of the wire.

[0004] The above-described techniques for manufacturing a flux-cored wire for welding stainless steel cannot achieve the goals of the present inventors to improve productivity and stabilize wire quality. Accordingly, it is an object of the present invention to improve the fluidity of a filling flux to prevent flux penetration and flux segregation during wire drawing, thereby achieving productivity improvement and wire quality stabilization.

[0005]

DISCLOSURE OF THE INVENTION The present invention has been studied in addition to the conventional method of manufacturing a flux-cored wire for welding stainless steel, in addition to the adjustment of the physical properties of the flux filled in the outer shell. As a result, after the flux is granulated using water glass, the synthetic mica, which is a lubricating material, is added to the granulated flux, so that the flux filled during wire drawing moves smoothly in the wire drawing direction. However, it has been found that the wire drawability is improved and the quality can be stabilized.

The present invention provides (1) a flux-cored wire for stainless steel welding, in which a flux composed of a slag agent and a metal agent is contained in an outer shell made of stainless steel in a total weight ratio of 10 to 25% by weight of the wire. A method for producing a flux-cored wire for stainless steel welding, comprising adding 0.05 to 0.20% of synthetic mica to the flux to improve drawability when filling, and performing wire drawing. . (2) The component of the synthetic mica is% by weight, and SiO ₂ : 40 to 50
%, MgO: 25~35%, Al 2 O 3: 6~15%, K 2 O: 5
-10%, F: 3-15%,
A method for producing a flux-cored wire for stainless steel welding according to (1). (3) A flux for stainless steel welding as described in (1) or (2), wherein the particle size of the synthetic mica is 70% or more when the particle size is 45 μm or less, and the maximum particle size is 425 μm or less. This is a method for manufacturing a wire.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The reasons for limitation in the present invention will be described below. First, a flux composed of a slag agent and a metal agent. If the flux is less than 10% of the total weight of the wire, it is difficult to secure welding workability and a target weld metal component. On the other hand, if it exceeds 25%, the thickness of the wire skin at the time of wire drawing is reduced, and there is a possibility that disconnection frequently occurs.

[0008] The reason for limiting to synthetic mica is that natural mica tends to vary in components depending on the place of production of the raw material,
This is because the maximum operating temperature is lower than that of synthetic mica and it is difficult to use. In addition, since synthetic mica is composed of the same components as the elements contained in the slag agent, the influence on the welding workability is small.

The main reason for limiting the amount of synthetic mica added in the present invention is that when the weight ratio of the wire is less than 0.05%, the effect of improving the smoothness of the flux is small and the effect of reducing the breakage during drawing is reduced. There was no. In addition, deterioration in the slag encapsulation and peeling properties was observed in welding workability, possibly due to uneven filling of the flux. It was found that when the content exceeds 0.20%, the welding workability, particularly the arc spraying becomes strong, and the workability is deteriorated.

Next, the composition of the synthetic mica is expressed as SiO ₂ : 4
0~50%, MgO: 25~35%, Al 2 O 3: 6~15%,
The reason for using K ₂ O: 5 to 10% and F: 3 to 15% is that the synthetic mica of the title component is mixed with the granulated flux when the individual particles are in the form of scales. It adheres to the surface of each particle of the granulated flux, and the lubricity is improved.

The reason for limiting the particle size of synthetic mica is as follows.
If the particle size is more than 5 μm, it is difficult to mix with the granulated flux, segregation is likely to occur, and the welding workability deteriorates. Therefore, the particle size of 45 μm or less is limited to 70% or more. If the maximum particle size is more than 425 μm, root clogging is likely to occur at the time of filling with the flux, and unfilling or segregation occurs to deteriorate welding workability. Therefore, the maximum particle size is limited to 425 μm or less.

The slag agent in the flux is mainly TiO ₂
In addition, SiO ₂ , ZrO ₂ , Al ₂ O ₃ , MgO, K ₂ O,
FeO, MnO, Na ₂ O, Bi ₂ O ₃ , NaF, Li
F, K ₂ ZrF ₆ or the like. The metal agent is used by adjusting the addition amount of each of them together with the target components of the deposited metal such as Ni, Cr, Mo, Mn, Fe, Nb, and stainless steel powder.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The effects of the present invention will be specifically described below. The flux having the composition shown in Table 3 was used for Na ₂ O, K ₂₀ , SiO ₂
After granulating with water glass composed of the following, the above-mentioned synthetic mica (shown in Table 1) was mixed and filled in the outer skin having the composition shown in Table 2, and a wire having the shape shown in FIG. 1 was drawn to 1.2 mmφ. After processing, welding was performed on the steel sheet and the welding conditions shown in Table 4, and the presence or absence of disconnection during manufacturing and comparison of welding workability were performed. In addition, the wire of the outer skin symbol A is applied to the steel sheet of steel sheet category 1,
The wire of the outer skin symbol B was welded to the steel sheet of the steel sheet section 2.

The test results are as shown in Table 5, and the wire N
o. All of the wires 1 to 12 had proper amounts of flux and synthetic mica, so that there was no disconnection in the wire drawing process. Good results were also obtained in welding workability. In contrast, No. Wires Nos. 13 and 17 did not break in the wire drawing process because the amount of added synthetic mica was appropriate, but the overall welding workability was poor due to the small amount of flux added.

No. The wires 14 and 18 were added with too much flux, so that the arc became unstable and the amount of spatter increased. No. Wires Nos. 15 and 19 did not contain synthetic mica, and thus breakage occurred during the drawing process. No. For the wires of Nos. 16 and 20, the amount of synthetic mica added was too large, so that the spraying of the arc became strong and the amount of spatter increased. The evaluation of welding workability in Table 5 was as follows: ○: good,
Δ: Slightly poor, ×: Poor, respectively.

[0016]

[Table 1]

[0017]

[Table 2]

[0018]

[Table 3]

[0019]

[Table 4]

[0020]

[Table 5]

[0021]

[Table 6]

[0022]

[Table 7]

[0023]

As described above, the present invention can prevent disconnection during wire production by mixing a predetermined amount of synthetic mica with the flux filling the inside of the outer cover made of stainless steel and stabilize the quality of the wire. It is intended.

[Brief description of the drawings]

FIG. 1 Cross section of flux cored wire

[Explanation of symbols]

 1 Skin 2 Filling flux

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Daisuke Watanabe 20-1 Shintomi, Futtsu-shi, Chiba Nippon Steel Corporation Technology Development Division

Claims (3)

[Claims] In a flux-cored wire for stainless steel welding, when a flux composed of a slag agent and a metal agent is filled into a sheath made of stainless steel at a wire weight ratio of 10 to 25% by weight, The flux contains 0.05 to 0.2 of synthetic mica for improving drawability.
A method for producing a flux-cored wire for welding stainless steel, comprising adding 0% and drawing. 2. The composition of the synthetic mica has a weight percentage of SiO ₂ : 40.
~50%, MgO: 25~35%, Al 2 O 3: 6~15%, K 2
The method for producing a flux-cored wire for stainless steel welding according to claim 1, wherein O: 5 to 10% and F: 3 to 15%. 3. The synthetic mica having a particle size of 45 μm or less
%. The method for producing a flux-cored wire for welding stainless steel according to claim 1 or 2, wherein the maximum particle size is 425 µm or less.