JPS6390388A - Flux cored wire for welding multiple tube and its manufacture - Google Patents

Abstract

PURPOSE:To manufacture the flux cored wire for welding a multiple tube by forming a band steel in semicircular arc shape with forming roll group, inserting a flux cored inner tube and hand-shaped adding material inside a semicircular arc shape band steel as well and performing a wire drawing as an integrated multiple pipe. CONSTITUTION:In manufacturing the flux cored wire for welding a multiple tube used for welding a low temp. steel, low alloy steel or high alloy steel, a band steel (h) is delivered from a supply stand S, and its sectional shape is formed in a circular shape 3 from circular arc shape 2 with forming roll groups 1-4 in order. At the time of its being formed in semicircular arc shape the inner pipe IP filled with the adding material AM of a linear or hand like Cr, Mo, etc., and a flux F is fed at the same speed as that of the band steel (h) steel and inserted onto the inner face of a semicircular arc shaped strip steel. It is subjected to a wire drawing by wire drawing devices 5-7, the multiple tube shape welding wire having the strip steel (h) as its sheath and incorporating the flux cored inner pipe IP and adding material AM is stably manufactured and wound on a winding machine 8.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a flux-cored wire for multi-tubular welding, which is used for welding low-temperature steel, low-alloy steel, low-alloy steel, etc., and a method for manufacturing the same.

(Prior Art) Conventional flux-cored wires used for welding low-temperature steel, low-alloy steel, etc. have mainly been the following two types of simple tubes.

[Part 1] is made by filling a jacketed metal tube made of a material with excellent workability with a flux containing a large amount of alloying components, and [Part 2] is made by filling a jacketed metal tube made of a material similar to the weld metal component with alloyed metal. It is filled with flux with a reduced component ratio.

(Problems with the prior art) Originally, when observing flux-cored wires in terms of arc phenomena during use, the internal flux column has a protruding shape compared to the arc length of the outer sheath metal. welding continues.

By the way, since the conventional wire described above as [Part 1] has a high alloy component ratio in the flux, the difference in specific gravity between the alloy component in the weld pool and the slag forming agent in the above arc phenomenon,
Another disadvantage is that the alloy components in the weld metal tend to segregate due to factors such as non-uniform stirring of the alloy components.

In addition, the conventional wire described above as [Part 2] is
Although there is no disadvantage in welding quality as in point 1), the outer metal tube is formed from steel strip containing a large amount of alloying components, and steel of such material has poor workability. In particular, the wire drawability is poor, and as a result, it is necessary to undergo two or three annealing processes from forming to wire drawing to produce a product, which is a factor that increases manufacturing costs. As a result, the company had no choice but to maintain its product prices at high prices, and was unable to adequately respond to the market's need to obtain good products at lower prices.

(Purpose of the Invention) The present invention has been made to solve the above-mentioned problems of conventional wires as flux-cored wires for welding low-temperature steel, low-alloy steel, etc. It is an object of the present invention to provide a flux-cored wire for multi-tubular welding, which is relatively easy to weld, and has stable welding quality, and a method for manufacturing the same.

(Process leading up to the invention) The present inventors have developed the first method to solve the problems existing in the prior art.
As a step, we prototyped a multi-tubular wire with the configuration described below.

In other words, an inner tube made of steel strip similar to the weld metal composition system is filled with flux having a low alloy composition ratio, and this is wrapped in a steel strip with excellent workability to form the outer skin. The welding quality obtained using the tube-shaped prototype wire is that there is no segregation of alloy components in the weld metal, and it is highly evaluated as a means of improving the wire itself. There is a large difference in workability due to the difference in composition between the inner tube and the outer tube, and the powdered flux filled in the inner tube does not promote the elongation of the inner tube, which has poor workability. A rupture of the inner tube was caused.

As a result of research on the [multi-tube prototype wire] and further research, the present inventors have arrived at the present invention shown below.

(Configuration of the first invention) The configuration of the first invention of the present application is as follows: (1) A desired additive material in the form of a line or band is inserted between the inner tube containing the flux and the outer skin surrounding the inner tube. The present invention relates to a flux-cored wire for multi-tubular welding, which is characterized in that it is made of a welding wire.

(Action of the first invention) The first invention of the present application has an effect of preventing the inner pipe and the additive material from breaking during wire drawing, and adding Since the material is integrated with the outer skin from which the arc emerges, it has the effect of extremely minimizing the segregation of alloy components in the weld metal.

(Configuration of the second invention) The configuration of the second invention of the present application, which is an invention of a method for manufacturing the wire of the present invention body 1, is as follows: (a) In the process of sequentially forming the band material into a tubular shape while running the band material, (a) the above-mentioned band material (C) A flux-cored inner tube formed by subjecting a strip material to a predetermined process and a desired additive material in the form of a wire or strip are simultaneously and sequentially fed onto the inner surface having an arcuate cross-section. A method for manufacturing a flux-cored wire for multi-tubular welding, characterized in that the material is formed into a tubular shape as an outer shell that envelops the inner tube and the additive material, and then drawn to a predetermined diameter (d1).

(Function of the second invention) The second invention of the present application easily forms a flux-cored wire for multi-tube welding with extremely low alloy component segregation in the weld metal without causing breakage in the inner tube or additive material. It has an effect.

(Example) The second invention of the present application will be described in detail below according to an example shown in the drawings.

In the figure, S is a supply stand on which the strip is wound, h is a strip made of a material with excellent workability, 1 to 4 are forming roll groups, and 5 to 7 are each equipped with a drawing die, etc. 8 is a winding machine. In addition, the IP was molded through a predetermined process using an outer skin made of a material with excellent workability. The inner tube with flux F as shown in cross-sectional view ■, AM is for example shown in cross-sectional view ■
They are strip-shaped additive materials, and are set so that they can be continuously supplied, for example, from a supply stand (not shown).

In the above configuration, the strip material supplied from No. Brystand S at a predetermined feed rate is sequentially formed from a circular arc shape to a circular cross section by the forming roll groups 1 to 4. 1, the inner tube is shaped into a ship's bottom shape as shown in cross-sectional view (■), and then passed through forming rolls 2 to become a semicircular arc shape as shown in cross-sectional view (■). IP and additive AM are inserted onto the inner surface of the semicircular arc via guide rolls T. Therefore,
The strip material that advances further is sequentially formed into a circular shape as shown in cross-sectional views (1) and (2) while enclosing the inner tube IP and the additive material AM by the forming rolls 3.4.

The multi-layered tube W, which has an outer skin made of strip material and contains an inner tube IP and additive material AM, is sequentially reduced in area to a predetermined diameter while passing through wire drawing devices 5 to 7, and is wound up by a winder 8. Becomes a product.

(Comparison with conventional methods, etc.) The present inventors compared the performance of the flux-cored wire W for multiple tube type welding according to the present invention and the workability in the manufacturing method to that of the conventional simple tube type [Part 1].

[Part 2], and the above-mentioned prototype produced in the process of arriving at the present invention.
A comparison was made with that of a multi-tube prototype wire.

This is shown in the attached table.

In the same table, Ni11 and No.7 are conventional type simple pipes [No. 1] that use strip steel with excellent workability as the outer skin and are filled with flux with a high alloy component ratio. Although the workability and the performance of the wire itself are good, segregation of alloy components occurs in the weld metal due to the high alloy component ratio of the internal flux.

Nl12 and No.8 are conventional type simple pipes [No. 2] that use a strip steel similar to the weld metal composition as the outer skin and suppress the alloy component ratio in the flux, and although there is no segregation of alloy components in the weld metal. The process of drawing the wire to the product size had poor workability, requiring intermediate annealing, which reduced the wire drawing speed and increased costs.

In addition, 11h3 and Magneto 9 are [multi-tube prototype wires] that the inventors tried in the process of arriving at the present invention, and there is no segregation of alloy components in the weld metal, or if there is, there is very little segregation.
Although the workability in the wire drawing process is also good, there is a large difference in workability between the outer skin and the inner tube, so that the inner tube itself sometimes breaks.

N[14,Il&15. 6. Number 10. and No. 11 are products to which the method of the present invention is applied, and have good workability in the wire drawing process, no breakage in the inner tube of the product wire, good finishing performance, and no alloy component segregation in the weld metal. It can be seen from the table that very good results were obtained without any problems.

In particular, additives that are made of materials with poor workability interposed between the outer skin and the inner tube are sandwiched by the extensibility of the outer skin and the inner tube, so that they can be easily processed until the product reaches a specified diameter.
It was clearly observed that the tumor was followed by distraction without rupture.

(Other Examples) The manufacturing example of the flux-cored wire W for multi-tubular welding according to the above-mentioned example merely shows the basic steps of the present invention.

For example, on-line parallel to the illustrated example process, a steel strip is formed into a tubular shape and filled with flux F to form a flux-filled inner pipe IP, and the inner pipe IP is shaped into a semicircular arc shape in the example process. The additive material AM may also be configured to merge with the additive material AM on the inner surface of the strip material.

In addition, in the above embodiment, the manufacturing method of the present invention was explained using an example in which the area of the multi-tube W with the outer skin made of strip material is reduced by the wire drawing devices 5 to 7.
After sealing with welding means such as G welding, wire drawing devices 5 to 7
Of course, it is also possible to send the data to . In this case, it is possible to widen the scope of application of the wire drawing technology in the next step, and the outer sheath itself can be wet-processed, thereby improving product performance.

Furthermore, in the comparative example in the attached table above, fflit%
2.25 Cr-I Mo steel, 3033168m
This is just an example of a wire for the same purpose, but it can also be used for combinations of outer shells, inner tubes, and additives other than those exemplified, or for other uses9, such as 1.25 Cr -0,5Mo customary use, SUS 309s1, etc. As for the wire, many combinations of outer skins, inner tubes, and additives other than those shown in the examples are possible. In any case, as long as the outer skin and inner tube are made of materials with excellent workability, good wire performance and welding performance can be obtained as the product to which the present invention is applied.

In addition, in the above example, the case where the additive material is a steel strip of alloy steel is explained, but the additive material is not limited to a single number, it is also possible to use a plurality of additive materials, and the additive material can be used in a single or plural number. Furthermore, it is possible to use not only alloy steel but also other component additives, and these operations have the effect of reducing component segregation in the weld metal, and also meet the design matters of the present invention. is within the range of

(Effects of the Invention) The present invention makes it possible to provide a flux-cored wire with stable welding quality for low-temperature steel, 2-low alloy steel, etc. at a relatively low cost, and has a tremendous effect of satisfying market needs. It is.

[Brief explanation of the drawing]

The figure is a front view of the basic manufacturing process for carrying out the method of the present invention. F ------1・-----1-----Flux I
P-・-1-------Inner tube h-------1--・---Outer skin = Band material A D
−−−−−・−−−−−−−One additive W−・−・−
−11−−−・−−−−1 Flux-cored wire for multiple tube type welding

Claims (1)

[Claims] 1) Multi-tube welding characterized in that a desired additive material in the form of a line or band is interposed between an inner tube containing flux and an outer skin surrounding the inner tube. flux-cored wire. 2) In the process of sequentially forming the strip into a tubular shape while running it,
Simultaneously and sequentially feeding a flux-cored inner tube formed by subjecting the band material to a predetermined process and a desired additive material in the form of a line or band onto the inner surface of the band material having an arcuate cross-section,
A method for producing a flux-cored wire for multi-tubular welding, characterized in that a strip material is formed into a tubular shape as an outer shell that envelops the inner tube and additive material, and then drawn to a predetermined diameter.