JP2003311470A - Method of producing flux cored wire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of producing a flux cored wire of excellent quality in which the packing density of flux in a longitudinal direction is uniform without reducing productivity. <P>SOLUTION: Flux of 4 to 10% by mass% to the total mass of the wire is stuck to the surface of a steel sheet, or the steel sheet is further subjected to forming so as to be a tubular shape while sticking the flux. After that, wire drawing is performed, so that the flux cored wire is produced. Preferably, the flux and an adhesive are previously kneaded, and the mixture is applied to the surface of the steel sheet. As the adhesive, water glass or polyvinyl alcohol is used. The flux is stuck to the surface of the steel sheet by thermal spraying. <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 method for producing a flux-cored wire which is often used in gas shielded arc welding when constructing steel structures such as buildings and bridges. The present invention relates to a method for producing a flux-cored wire, which is capable of producing a wire having an extremely small uneven distribution of flux and an excellent weld metal composition stability with high production efficiency.

[0002]

2. Description of the Related Art In general, a wire used for gas shielded arc welding contains a predetermined amount of a metal component used for adjusting weld metal characteristics, and other alloy wire containing Fe as a main component is drawn. The solid wire produced by and the outer shell mainly composed of Fe are filled with fluxes such as oxides and fluorides for maintaining good arc stability and weldability such as bead shape. Further, it is roughly classified into a flux-cored wire in which either or both of the outer coat and the flux contain a metal component used for adjusting weld metal properties. In general, flux-cored wires are superior to solid wires in terms of arc stability during welding work, bead shape, etc. due to the addition of oxides and fluorides in the flux. Is increasing.

In the conventional method for manufacturing a flux-cored wire, a steel plate (tape-shaped) which is a wire outer material is rolled and formed into a tubular shape while flux is added to form a steel pipe containing the flux. Furthermore, a method of wire drawing to make a wire with an outer diameter of 1 to 1.6 mm, a flux is filled from the end of a steel pipe that serves as a wire sheath material while applying special vibration, and wire drawing is applied to the outside. Diameter: 1 to
A method of forming a wire rod of 1.6 mm, a flux is added in the middle of forming a steel plate serving as a wire sheath material into a tubular shape,
There is a method of forming a steel pipe containing flux by seam welding the steel plate butt portions and then wire drawing to form a wire having an outer diameter of 1 to 1.6 mm.

Conventionally, in any of these methods, if the flux filling rate exceeds about 20%, there is a tendency that a wire breakage easily occurs during the wire drawing process of the steel pipe containing the flux. As a result, the drawing speed is slowed down or the upper limit of the flux filling rate is restricted to about 20%. However, even when the flux filling rate is 20% or less or when the drawing process is slowed, it has not been possible to completely prevent the occurrence of disconnection during the drawing process, and the cause thereof has not been clearly known. , Causing a drop in productivity.

[0005]

DISCLOSURE OF THE INVENTION The present invention solves the problems of the prior art as described above, and achieves quality with a uniform flux packing density in the longitudinal direction of the wire without lowering productivity. An object is to provide an excellent method for manufacturing a flux-cored wire.

[0006]

The present invention is intended to solve the above-mentioned problems, and the gist thereof is as follows, as set forth in the claims. (1) Flux characterized in that 4 to 10% by mass% of the total mass of the wire is fixed to the surface of the steel plate, or the steel plate is formed into a tubular shape while being fixed and then drawn. Manufacturing method of cored wire. (2) The method for producing a flux-cored wire according to (1), characterized in that the flux and the adhesive are mixed in advance and the mixture is applied to the surface of the steel sheet to fix the flux to the surface of the steel sheet.

(3) The method for producing a flux-cored wire according to (2), characterized in that water glass or polyvinyl alcohol is used as the adhesive. (4) The flux-cored wire according to (1), characterized in that the flux is fixed to the surface of the steel sheet by spraying the flux onto the surface of the steel sheet or spraying a suspension of the flux and a volatile solvent onto the surface of the steel sheet. Production method. (5) The method for producing a flux-cored wire according to any one of (1) to (4), characterized in that one side of the steel sheet is processed to have a protrusion, and the surface having the protrusion is inwardly formed into a tubular shape. (6) Steel plate, in mass%, C: 0.008 to 0.16
%, Si: 0.05 to 0.8%, Mn: 0.2 to 1.5
%, With the balance being Fe and inevitable impurities, the method for producing a flux-cored wire according to any one of (1) to (5).

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below. As a result of intensive studies by the present inventors, the cause of disconnection during the drawing process in the flux-cored wire manufacturing process is not limited to the fact that the flux filling rate and the drawing speed are too high, and the flux before the drawing process is included. It was found that the variation in the amount of flux in the longitudinal direction of the formed steel pipe greatly affects the occurrence of wire breakage during wire drawing.

The variation in the amount of flux in the longitudinal direction of the steel pipe is caused by a method of filling the inside of the steel pipe with a flux while vibrating a steel pipe having an outer diameter of 10 to 25 mm, or a steel plate having an outer diameter of 1 mm.
It occurs in any of the methods in which flux is added during molding into a tubular shape of 0 to 25 mm.
When narrowing down to 1.6 mm by wire drawing processing, the narrowing amount increases only in the portion where the flux amount is small due to a slight variation (uneven distribution) of the flux in the longitudinal direction, and as a result of local narrowing, disconnection is likely to occur. Become. It was found that this tendency of breakage became remarkable as the flux filling rate and the drawing speed increased. The present invention is
It was made based on the above findings, in the method of manufacturing a flux-cored wire, after fixing a predetermined amount of flux to the surface of the steel plate of a predetermined component (the side corresponding to the inner surface of the steel pipe) to be the wire skin, or While fixing, a method of forming this steel plate into a tubular shape, or using a steel plate having a projection on one side surface as the steel plate, adding flux to the projection processing surface of this steel plate, and carrying it,
This method is characterized by suppressing the variation of the flux amount in the longitudinal direction in the steel pipe before wire drawing by the method of forming into a tubular shape so that the projection processing surface of the steel plate is on the inside.

1 and 2 show a first embodiment of the present invention in which a flux 1 and an adhesive (binder) 2 are kneaded in advance to form a soft clay or slurry (Note: slurry,
The schematic diagram of the method of apply | coating the mixture in the form of mud and solid fine particles) to the steel plate surface to fix the flux 1 on the steel plate surface, and then forming this into a tubular shape is shown. A first embodiment of the present invention will be described with reference to FIG. A powder-like flux 1 and a caking material (adhesive 2) such as water glass are kneaded to produce a slurry-like or soft clay-like mixture, which is attached to one surface of a tape-like outer steel plate and a rubber roller 5 Figure 1 shows the process of applying and fixing via
Shown in. In the coating step, the flux 1 is spread and coated uniformly in a desired thickness so that the filling rate is as prescribed. Since moisture in the welding material causes hydrogen cracking in the main welding, it is desirable to avoid as much as possible a material containing moisture and a large amount of hydrogen in the molecule as the caking material.

FIG. 2 shows a continuous forming process, seam welding and wire drawing process. The tape-shaped outer steel sheet 11 having the flux adhered to one surface is rounded in the forming step 13 and formed into a tubular shape having an outer diameter of 10 to 25 mm. The abutting portion of the outer skin has an overlap margin of about 0-2 mm, and this portion is completely sealed by seam welding 15 performed by TIG welding 14. Finally, a flux-cored wire having a predetermined final diameter (1.0-1.6 mm) is manufactured by sequentially passing through a drawing die and performing a drawing process 16 step by step. Further, the spread of the flux on the steel sheet is not limited to the total amount of the flux, but a part (preferably 45% or more of the flux) of the flux may be used, or a part of the specific component may be spread easily, and the clay-like product may be spread. After depositing, the remaining powder, which is a powder, can be evenly sprayed on it, and when processed into a pipe, mutual flow between the residual flux inside the pipe and the already spread flux causes As a result, uneven distribution can be prevented.

The pressure-sensitive adhesive in the present invention is preliminarily added to and mixed in the flux and spread on the surface of the steel plate for the outer cover, and then formed into a tubular shape. It is necessary to obtain an adhesive force or an anti-slip effect to the extent required to prevent uneven distribution. For example, an adhesive (caking material) such as water glass or polyvinyl alcohol is preferable as the pressure-sensitive adhesive having such an adhesive force or an anti-slip effect. As a second embodiment of the present invention, FIG. 3 shows a schematic diagram of a method of depositing the flux 21 on the surface of the outer steel sheet by powder flame spraying. Second of the present invention with reference to FIG.
Will be described.

The thermal spraying was performed by using a mixed gas of oxygen 24 and acetylene 23 as a heat source and using a thermal spray torch 22 to supply a powder-like flux into the combustion flame. When the filling rate of the flux is relatively low, it is possible to spread the flux by spraying a suspension of the flux with a volatile solvent such as alcohol. Both the spraying process and the spraying can be performed under atmospheric pressure. The thickness of the flux deposited on the outer steel sheet was adjusted by the spraying conditions and the feeding speed of the outer steel sheet. Subsequently, a wire is formed through a forming step, a seam welding step, and a wire drawing step. This step is the same as the step shown in FIG. As a third embodiment of the present invention, FIG. 4 shows a schematic view of a method of using a steel sheet having a projection processing on one side surface thereof, and adding and carrying a flux on the projection processed surface of the steel sheet. A third embodiment of the present invention will be described with reference to FIG.

For the projection processing applied to one surface of the steel plate 31 used as the outer material, an automatic chisel 32 or a coarse knurl 36 was used. By this step, shallow dents and protrusions are obtained on the surface of the outer steel sheet in the case of the automatic chisel 32, and fine grooves or fine irregularities are obtained in the case of using the knurl 36. Continuously, the powdery flux is uniformly supplied to the processed surface. Flux becomes a situation where it is uniformly buried in these processed dents and grooves, and even if it is not completely filled, it is evenly supported in the tube after processing into a tube due to friction with the previously filled flux. This has the effect of preventing uneven distribution of flux in the wire longitudinal direction. Furthermore, on a flat steel plate that has been subjected to protrusion processing,
It is also possible to spread a clay-like flux mixture obtained by mixing the flux and the adhesive material by thinly spreading it.

Next, a wire is formed through a forming step, a seam welding step 35, and a wire drawing step 37 in a continuous manner. This step is the same as the step shown in FIG. As the skin material, mild steel having good workability is usually used, but Ni and C are used to further adjust the characteristics of the weld metal, if necessary.
Alloying components such as r and Mo are contained, and the components are designed so as to be a weld metal that matches the performance of the material to be welded by the interaction with the metal components in the filling flux.

As a component of the flux filled inside the outer shell, a synergistic action with the components of the outer shell material is used, so that the characteristics such as strength and toughness of the weld metal are compatible with the steel material to be welded. At C, Si, Mn, Cu, Ni, C
Components such as r, Mo, Nb, V, Ti, and B are added in appropriate amounts, and arc stability, bead shape (slag fluidity,
In order to secure good welding workability such as slag skin encapsulation), TiO ₂ (rutile), SiO ₂ (silica), Al ₂ O ₃
An oxide such as (alumina) or a fluoride is added.
In many cases, the flux is used by adding water glass or the like in advance and mixing it in the form of granules so that the outer skin can be uniformly filled.

Flux-cored wire is manufactured with an outer diameter of 10
A steel pipe having flux contained therein is prepared by filling a flux into the steel pipe while vibrating a steel pipe having a diameter of ~ 25 mm, or by adding a flux while forming a steel plate into a tubular shape having an outer diameter of 10 to 25 mm. It is manufactured by drawing an outer diameter of 1 to 1.6 mm. The steel sheet used in the present invention has good workability when it is narrowed down by a drawing process before or after forming it into a tubular shape, after fixing or supporting a flux, and after forming it into a tubular shape. Good weldability is required in seam welding performed to seal the seal. Therefore, in order to obtain these characteristics, it is necessary to properly limit the chemical composition of the steel sheet used as the skin material of the flux-cored wire.

The reasons for limiting the chemical composition of the steel sheet used as the skin material of the flux-cored wire of the present invention will be described below. In addition, unless otherwise indicated,% shown below shall show mass%. The content of C is 0.008 to 0.16 mass%. This is 0.008
If the amount is less than%, the strength is insufficient, the circularity is reduced when the material is formed into a tubular shape, and the hardness of the product wire is insufficient, resulting in unstable wire feeding during welding. On the other hand, if it exceeds 0.16%, the seam weld becomes too hard, and it becomes difficult to perform wire drawing. Furthermore, the unevenness of the cross-sectional hardness distribution of the wire causes bending of the wire, which also causes unstable feeding of the wire during welding, resulting in a large deviation of the wire tip.

Si has a content of 0.05 to 0.8%.
And Si ensures proper fluidity of molten steel during seam welding and enables good seam welding, and promotes deoxidation of molten steel to prevent the formation of pores. However, if it is less than 0.05%, there are problems that the flow of the molten weld metal is bad and that pores are observed. on the other hand,
If it exceeds 0.8%, the weld strength becomes too high and the same phenomenon as excessive strength due to high C occurs, so 0.8% was made the upper limit. Mn functions as a proper strength and a deoxidizer, and its content is 0.2 to 1.5%. If it is less than 0.2%, insufficient deoxidation during seam welding occurs, and if it exceeds 1.5%, cracking is recognized. The other components are not particularly limited, but if necessary, those components are adjusted depending on the purpose thereof in order to adjust the components in the weld metal by synergistic action with the components added in the form of metal or alloy from the flux. Alloying elements can also be added.

In general, it is preferable that P and S are as small as possible from the viewpoint of mechanical performance of the welded portion. However, since P has a function of enhancing the corrosion resistance, P may be added in an appropriate amount for the purpose of improving the corrosion resistance of the weld metal. Further, S has an effect of improving the slag releasability, so S may be added in an appropriate amount for the purpose of improving the slag releasability of the weld metal. Ni, Mo, Cr,
Ti, Cu and the like can also be added in an appropriate amount of 2% or less for the purpose of improving the mechanical performance of the weld metal or improving the corrosion resistance. In the case of special steel such as stainless steel, Ni, Cr, etc. may be about 25%.

Further, in the present invention, the total mass of the flux filled in the wire sheath is 4 to 3 with respect to the total mass of the wire.
Limited to 0%. The reason for setting the lower limit of the filling rate is that when the filling rate is lower than 4%, the arc is softened by the action of oxides or fluorides contained in the flux, or the bead shape is improved. The effect is not fully obtained,
This is not because of manufacturing reasons, but because the original advantages of the flux-cored wire are lost. Further, the reason why the upper limit of the filling rate is set is that when the filling rate exceeds 30%, when the wire diameter is drawn to 1 to 1.6 mm as the final product, the outer skin becomes relatively thin. This is because the outer skin may be broken when an external force such as bending is applied during the drawing process or during use.

[0022]

EXAMPLES The effects of the present invention will be described below with reference to examples of the present invention. Table 1 shows the composition of the steel sheet used as the skin material of the flux-cored wire. In Table 1, A,
B and B′C are steel plates having a composition within the scope of the present invention,
D, E, and F are steel plates having a composition outside the scope of the present invention. Steel plate size is 1mm, width 16 except B '.
mm, and only B'has a plate thickness of 0.5 mm and a width of 16 mm.

Table 2 shows the filling rate of the flux filled in the outer cover (ratio of the total amount of flux to all wires (mass%)), the anti-slip method, the wire drawing speed and the evaluation results thereof. The flux is a component system called rutile system, the oxide is mainly composed of TiO ₂ , and SiO ₂ and A
l ₂ O _3, 6 as the blending ratio of Na ₂ O or the like in addition oxide
%, The compounding ratio of alloying components such as Si and Mn among the metal components was 54%, and Fe was 40% as the basic composition. However, for those with a small flux addition amount (filling amount) of 3 and 4%, the Fe compounding ratio was 10%.

A steel sheet having the composition shown in Table 1 was used as a skin material,
A flux-cored wire was manufactured using the flux having the filling rate shown in Table 2 according to the method of fixing or supporting the flux on the steel plate and the drawing speed. The wire manufacturing conditions other than the method of fixing or supporting the flux on the steel plate are as follows: After the fixing of the flux, while fixing, supporting, or simply adding the flux, the steel plate is processed into a tube having an outer diameter of 12 mm, and Seam welding was performed by TIG, and this was drawn into a wire having a diameter of 1.2 mm. However, Table 1
Only when the steel plate B'having a plate thickness of 0.5 mm shown in (1) was used as a skin material, wire drawing was performed without seam welding of the steel pipe abutting portion after forming into a tubular shape.

Each flux-cored wire was evaluated from the workability during wire production and the weldability during wire use.
The results are shown in Table 2. The workability evaluation at the time of wire production is
Judging by the occurrence of crushing and wire breakage during wire drawing processing,
⊚: Very good ◯; Good Δ: Slightly problematic X: Poor The weldability of the wire was evaluated by observing the stability of the arc and the bead shape when welding under the conditions shown in Table 3. ∘ and ∘ were passed as a comprehensive evaluation from the workability in manufacturing these wires and the weldability in using the wires. Examples No. 1 to No. 6 shown in Table 2 are examples of the present invention, and Examples No. 7 to 10 are the component composition of the steel sheet used as the outer covering material, the flux filling rate, or the sticking or carrying of the flux to the steel sheet. It is a comparative example in which at least one of the methods is out of the scope of the present invention.

Implementation NO. 1 is a flat steel plate C, and has a flux amount of 6%, and Fe in this flux is sprayed and adhered onto one surface of the flat steel plate, and the remaining flux is added onto this to form a tubular shape, After seam welding the joint portion with TIG, wire drawing was performed at a high speed of 30 m / sec with a diameter of 1.2 mm. There was no abnormal shape in the seam welded part, and the wire was processed at a high speed, but the wire could be processed smoothly. As a result of welding under the welding conditions shown in Table 3, the arc is stable due to the addition of the sharpness of the solid wire, and the bead is a smooth and good bead, which is a characteristic of the flux-cored wire. -The appearance was good, and welding was performed with good penetration. The amount of slag was smaller than that of the conventional flux wire, and even if 6-layer continuous welding was performed without removing the slag, no adverse effect of the slag was observed, and high-efficiency welding was possible.

Implementation NO. 2 and 3 are flat steel plates B and A, and have a flux amount of 8 and 4%. The flux is premixed, and granules having a diameter of 0.1 to 1 mm are granulated using water glass. Water glass or PVA (polyvinyl alcohol) was applied onto the surface of the flat steel plate, and then dropped, and the wire was worked under the same conditions as in Example 1. Also in this example, smooth wire processing was possible. In the welding test, a phenomenon in which a large amount of fume was observed was observed, but the arc was stable as in Example 1, the amount of slag was appropriate, and the bead shape was also good.

Implementation NO. No. 4 uses flat steel plate A, and the amount of flux is 10%. After the Si alloy in this flux is sprayed, the steel pipe is processed while adding the remaining flux,
Welded and drawn. However, since the amount of flux added was large, the drawing speed was slightly slow, and the drawing speed was 25 m / sec. This also enabled smooth wire processing. The welding test results showed that the arc was stable, the amount of slag was moderate, and the bead shape was good, as in Example 1. Implementation N
O. 5 is flat steel plate B '(thickness t 0.5 mm), the flux amount is 8%, and this flux is processed into granules, and is processed into a steel pipe while being added onto the flat steel plate coated with PVA. Wire drawing was performed without seam welding. However, since there was no seam welding, the drawing speed was 25 m / sec. This also enabled smooth wire processing. In the welding test, there was a lot of fume, and the deflection at the wire tip was large, but the arc was stable and the beam was
The shape was also good.

Implementation NO. No. 6 was a flat steel plate A, and an automatic chisel was used on one surface of the flat steel plate A, and radish-shaped projections of 0.2 mm height were attached in a staggered arrangement of 3 mm pitch. A flat steel plate was formed into a tubular shape while filling a granulated product in the same manner as in Examples 2 and 3 with a flux filling amount of 7%, and the butt portion was seam welded by TIG, and then the diameter was 1 Wire drawing was performed at a high speed of 25 mm / sec at 0.2 mm. There were no abnormal parts in the seam welds, and smooth wire processing was possible. In addition, the welding test results showed that the arc was stable due to the sharpness of the solid wire. The beads had a smooth and good bead appearance, which is a characteristic of the flux-cored wire, and the penetration was also good.

Implementation NO. In Comparative Example 7, a flat steel plate C was used, and the flux amount was 8%. The flux was formed into granules, and the steel pipe molding, seam welding, and wire drawing were performed. Crushing occurred in the wire drawing process, and in the welding test, there were pores caused by the absence of flux, and stable welding could not be performed. Implementation NO. 8
In the comparative example, the ultra-soft steel D was used as the flat steel sheet, and the flux amount was 3%. The flux was formed into a granular shape, and the flux was subjected to steel pipe forming, seam welding, and wire drawing. Deflection due to softness occurred in the steel pipe forming process, and unevenness was generated in seam welding due to insufficient fluidity of molten steel. Even in the welding test, the soft arc, which is a characteristic of the flux-cored wire, was not seen, and the bead shape was unstable.

Implementation NO. 9 is also a comparative example, the flat steel plate is Si,
E with high Mn was used, and the flux amount was 12%. The flux was subjected to steel pipe molding, seam welding, and wire drawing while simply adding granular ones. It was recognized that fumes tended to occur frequently in seam welding, and probably because the tube was too hard, a triangular portion was generated even though the drawing speed was reduced to 20 m / sec. The welding test was almost the same as the conventional flux-cored wire. Implementation NO. 10
In a comparative example, F having a high C was used as the flat steel sheet, and the flux amount was 8%. The flux was formed into a granular shape, and the flux was subjected to steel pipe forming, seam welding, and wire drawing. Since the seam welded portion had a high C and became hard, it became triangular in the subsequent drawing step. Also in the welding test, some places where porosity was generated due to lack of flux.

[Table 1]

[Table 2]

[Table 3]

[0032]

According to the present invention, it is possible to provide a method for producing a flux-cored wire which is excellent in quality with uniform packing density of flux in the longitudinal direction without lowering productivity. The flux-cored wire for gas shield arc welding of the present invention is a wire having the characteristics of a flux wire while maintaining the characteristics of a solid wire, and is intended to be produced and processed with high efficiency. It is possible to improve quality and productivity. This greatly contributes to quality improvement and economic efficiency improvement in the field of steel processing and assembly.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a method of fixing a flux to a steel plate surface by previously mixing a flux and an adhesive and applying the mixture to the steel plate surface as a first embodiment of the present invention.

FIG. 2 is a diagram showing a forming process, a seam welding process, and a drawing process process, in which a tape-shaped outer steel sheet having a flux adhered to one surface thereof is rolled into a tubular shape and carried out according to the present invention.

FIG. 3 is a schematic view of a second embodiment of the present invention, which is a method of forming a tubular shape while fixing flux on the surface of a steel sheet by thermal spraying.

FIG. 4 is a schematic diagram of a third embodiment of the present invention, in which a protrusion is formed on one surface of an outer steel plate, and a tube is formed while a flux is added and carried on the protrusion-treated surface of the steel plate. is there.

[Explanation of symbols]

1: Flux, 2: Adhesive (binder), 3: Slurry of flux, 4: Stirrer (stirring blade), 5: Rubber roller for application, 6: Spreaded flux, 7: Steel sheet, 11: Flux spread Coated outer steel plate, 12: guide roller, 13: forming step (rolling up), 14: TI
G welding, 15: seam process, 16: wire drawing process, 21:
Flux, 22: Flame spraying torch, 23: Fuel gas (acetylene), 24: Oxygen gas, 25: Powder supply gas, 26: Frame containing flux, 27: Spread flux film, 28: Skin steel plate, 31 : Outer steel plate,
32: Automatic chisel, 33: Guide roller, 34: Flux feeder, 35: Forming process (rolling), 36: Knurl, 37: Drawing process

Continued front page    (72) Inventor Shigeru Okita             20-1 Shintomi, Futtsu-shi, Chiba Nippon Steel shares             Company Technology Development Division

Claims (6)

[Claims] 1. A mass% based on the total mass of the wire, 4-1.
A method for producing a flux-cored wire, which comprises forming 0% flux on a surface of a steel sheet, or forming the steel sheet into a tube while fixing the flux, and then drawing. 2. The method for producing a flux-cored wire according to claim 1, wherein the flux and the adhesive are mixed in advance and the mixture is applied to the surface of the steel sheet to fix the flux to the surface of the steel sheet. 3. The method for producing a flux-cored wire according to claim 2, wherein water glass or polyvinyl alcohol is used as the adhesive. 4. The flux according to claim 1, wherein the flux is fixed to the surface of the steel sheet by spraying the flux onto the surface of the steel sheet or spraying a suspension of the flux and a volatile solvent onto the surface of the steel sheet. Wire manufacturing method. 5. The method for producing a flux-cored wire according to claim 1, wherein one surface of the steel sheet is processed to have a projection, and the surface having the projection is inwardly shaped into a tubular shape. . 6. The steel sheet, in mass%, C: 0.008-
0.16%, Si: 0.05 to 0.8%, Mn: 0.2
6. The method for producing a flux-cored wire according to claim 1, wherein the flux-containing wire contains ˜1.5%, and the balance is Fe and unavoidable impurities.