JPS61286091A - Production of flux-cored wire for welding - Google Patents

Abstract

PURPOSE:To eliminate the disconnection during drawing and to improve the productivity and yield of a flux-cored wire for welding by setting the ratio between the max. diameter of the granular residual matter below the specific size in a metallic pipe and the inside diameter of the metallic pipe after drawing to a specific ratio or below in the drawing of the above-mentioned wire. CONSTITUTION:The ratio between the max. diameter of the granular flux, sized <=0.5mm, existing in the flux-cored and seam-welding metallic pipe for welding and the inside diameter of the metallic pipe is set at <=0.85. The flux has good fluidity if the metallic pipe having such conditions is drawn. In addition, the fluid resistance by the spatters and residual inclusions during seam welding is made harmless and the disconnection in the drawing stage of the metallic pipe is eliminated. The productivity and yield of the flux-cored wire for welding is thus improved.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Field of Application) This invention relates to the production of a welding flux-cored wire that is used to produce a welding flux-cored wire in which a metal tube is filled with flux. It is about the method.

(Conventional technology).

Conventionally, there are various welding methods, including those using electrical energy, those using chemical energy, those using mechanical energy, and those using light energy.

Among these, there are various methods that utilize electrical energy, such as arc welding, resistance welding, high frequency welding, electron beam welding, and plasma welding.

Among these, arc welding methods include methods using coated arc welding rods, methods using solid wire,
There are methods that use flux-cored wire, such as submerged arc welding that uses solid wire, and gas-shielded arc welding and non-gas-shielded arc welding that use flux-cored wire, which are welded semi-automatically or fully automatically. This method has become widely used in recent years.

Flux-cored wire for welding can be produced by filling a seamless metal tube with flux and drawing it, forming a steel strip and filling the inside with flux and drawing it, or forming a steel strip and drawing it. It is manufactured by a method such as molding, filling the inside with flux, joining the joints, and then drawing wire.

(Problems to be Solved by the Invention) By the way, when it is attempted to manufacture a flux-cored wire for welding by filling such a metal tube with flux and drawing it, wire breakage may occur in the wire drawing process. there were.

Therefore, in order to prevent wire breakage during the wire drawing process, various experiments have been attempted on the area reduction rate during wire drawing, the wire drawing speed, the hardness of the metal tube, the particle size of the flux powder, etc.
Even so, there was still a problem that wire breakage could occur during wire drawing.

This invention was made by focusing on such conventional problems, and when producing a flux-cored wire for welding by filling a metal tube with flux and drawing the wire, it is possible to prevent wire breakage in the wire drawing process. As a result of various experiments conducted with the aim of preventing K from occurring, we found that residues inside metal tubes, which had not been considered at all in the past, such as spatter that occurs when forming metal tubes by welding and when filling with flux, were found. This invention was completed after confirming that fine residues such as foreign matter mixed in the wire had an adverse effect during wire drawing.

[Structure of the Invention] (Means for Solving the Problems) This invention provides a method for producing a welding franked wire by filling a metal tube with flux and drawing the metal tube. However, as a metal tube in which the ratio (L/d) of the maximum particle size (L) of the particulate residue to the inner diameter (d) of the metal tube after wire drawing is 0.85 or less, The feature is that the wire is drawn after being filled with flux.

In the flux-cored wire for welding produced according to the present invention, the components of the metal tube and flux are not particularly limited, and the components of the metal tube and flux (such as slag forming agents and arc stabilizers) of the flux-cored wire for welding are not particularly limited. ) can also be used.

In addition, metal pipes often contain residual spatter or other foreign matter during pipe manufacturing, such as grain-like, fibrous, or powder-like foreign matter. Of these! Since the lI fibrous cross-shaped residue tends to remain long in the drawing direction during wire drawing, it is less likely to cause wire breakage during wire drawing, as in the case where the residue is in the form of powder.

Particulate residue is likely to cause wire breakage during wire drawing, and in this case, the ratio of the maximum particle diameter (L) of one particulate residue to the inner diameter (d) of the metal tube after wire drawing (L /d) is 0.8
Particulate residue in the metal tube should be limited in advance to less than 5%. In this case, for example, when manufacturing metal pipes by resistance welding, it is possible to select welding conditions that minimize the occurrence of spatter with large particle diameters, and also to prevent the occurrence of spatter with large particle diameters. If this cannot be sufficiently prevented, the metal pipe is cleaned after pipe making to remove large particle size residues.In this case, the maximum particle size of the particulate residue inside the metal pipe is 0.
It has been confirmed through various experiments that it is desirable to set the thickness to 5 mm or less.

(Example) The metal tube is made of mild steel and has an outer diameter of 8.0 mm.
Use one with a wall thickness of 1.5 mm, and use it as a flux.
Rutile: 50ffiffi%, Zircon: 10% by weight
Feldspar: 5% by weight, Fe-Mn+25% by weight, Fe-3i
:10% by weight was used.

Next, the metal tube was filled with a flux having the above composition, and then wire-drawn until the inner diameter of the metal tube reached the size shown in the following table, and the presence or absence of wire breakage during wire drawing was examined. The results are also shown in the table.

As shown in the table, many disconnections occurred when the maximum dimension of the particulate residue was large and the ratio (L/d) to the inner diameter of the metal tube was larger than 0585, whereas when the above ratio was If the ratio is 0.0585 or less, there will be less disconnection, and if the above ratio is 0.
When the temperature was 70 or less, no wire breakage occurred at all.

[Effects of the Invention] As described above, according to the present invention, in the method for manufacturing a flux-cored wire for welding by filling a metal tube with flux and drawing the wire, particulate residue in the metal tube is removed. However, the maximum particle size of the particulate residue (
Since the metal tube has a ratio (L/d) of 0.85 or less between L) and the inner diameter (d) of the metal tube after wire drawing, the metal tube is filled with flux and wire drawn. This is an extremely excellent method that can significantly reduce the occurrence of wire breakage during wire drawing, improve productivity of welding flux-cored wire, increase yield, and reduce manufacturing costs. effect is brought about.

Claims (2)

[Claims] (1) In a method of manufacturing a flux-cored wire for welding by filling a metal tube with flux and drawing the wire, the particulate residue in the metal tube has a maximum particle size (L) of the particulate residue. A welding flux characterized in that the metal tube has a ratio (L/d) to the inner diameter (d) of the metal tube after wire drawing of 0.85 or less, and is drawn after filling the metal tube with flux. Method of manufacturing cored wire. (2) The maximum particle size of particulate residue in the metal pipe is 0.5m
A method for manufacturing a welding flux-cored wire according to claim (1), wherein the flux-cored wire is less than or equal to m.