JP2914763B2 - How to connect hoop material for powdered wire - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for connecting a hoop material used for a powder-filled wire obtained by filling a metal tube made of carbon steel, stainless steel, copper alloy, aluminum alloy or the like with powder. Here, the powder refers to powder such as welding flux and oxide superconducting material. INDUSTRIAL APPLICATION This invention is utilized for manufacture of the flux cored wire for welding, the wire containing an oxide superconducting material, and other powdered wires.

[0002]

2. Description of the Related Art As one of powdered wires, there is a flux-cored seamless wire for welding. In the production of this seamless wire, the cold-rolled steel strip is slit to a required width, and the hoop material after the slit is gradually formed from a U-shape to an O-shape by a forming roll. During this molding, the flux is supplied to the valley of the hoop material by a feeder from an opening along the longitudinal direction of the U-shaped hoop material. Next, at the same time as the O-shape is formed, the opposite edge surfaces of the opening are joined by welding, and subsequently the diameter is reduced. Further, after annealing as required, the tube filled with the flux is drawn to a desired diameter and wound up to obtain a product.

[0003] In the production of such a powdered wire, the rear end of the preceding hoop material is connected to the front end of the succeeding hoop material in order to produce the wire continuously without interruption. Conventionally, connection between hoop materials is performed by temporarily attaching metal tab materials 4 and 5 to both sides of a welding wire 3 formed by joining a hoop material 1 and a hoop material 2 to be connected as shown in FIGS. Weld 6. Next, the copper plate 7 is applied to the back side of the welding wire 3, welding is started from one tab material 4 (start point S), welding of the hoop materials 1 and 2 is performed continuously, and welding is performed with the other tab material 5. End (end point E). The welding is a one-sided butt welding. This tab material is used for the purpose of releasing a poorly welded portion or a crater at an end portion generated at a welding start portion onto the tab material and obtaining a good welded portion over the entire length of the butt welding line 3 of the hoop material. After welding, the metal tab material 4 and the tab material 5 are cut and removed.

[0004] The fixing of both hoop materials to the welding position is as follows.
The butt welding line 3 is aligned with the groove of the copper plate 7, the hoop members 1 and 2 are arranged between the support plate 8 and the holding plate 9, and the holding plate 9 and the supporting plate 8 are fixed by a fastening jig (not shown). The two hoop members 1 and 2 are fixed by tightening.

[0005]

However, in such a conventional connection method of a hoop material, a melt-down phenomenon of a molten pool occurs at both ends 3S and 3E of a butt welding line 3 of both hoop materials 1 and 2. There was a drawback that it was easy to do. If the molten pool melts down during welding, the arc will be cut or holes will be formed. When a hoop material having a defect at such a connection portion is used for manufacturing a powder-filled wire, the hoop material cannot withstand reduction in diameter to the product diameter, and the connection portion between the hoop materials is disconnected. Therefore, when burn-through occurs, the end of the hoop material must be cut again and set again,
It was troublesome and time-consuming, and was uneconomical.
SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for connecting a hoop material in which a molten pool does not melt off at both ends of a butt welding line of both hoop materials.

[0006]

A method for connecting a hoop material for a powder-filled wire according to the present invention, which achieves the above object, comprises a tab material.
Tabs so that the end faces touch the side of the hoop material
Each place wood on both sides of the hoop material, after welding with temporary by arc spot welding points of contact with butt weld line and tab member end face, to one side welding a butt weld line. The hoop material is a hoop made of carbon steel, stainless steel, a copper alloy, an aluminum alloy or other metal, and has dimensions of about 50 to 100 mm in width and about 1.5 to 3.5 mm in thickness. The butt welding line of both hoop materials shall be perpendicular to the longitudinal direction of the hoop material,
It may be inclined. The angle of inclination with respect to the longitudinal direction of the hoop material is 10 degrees or more, preferably 30 to 80 degrees. When the wire is inclined, the welding wire becomes longer, but there is an effect of dispersing the load acting on the connection portion of the wire in the rolling and drawing processes during the manufacturing process of the flux cored wire for welding. Single-sided welding is welding in which an appropriate backing material, for example, a metal (mainly copper) backing metal, solid flux, or the like is used to perform welding from one side to form a back bead, and the back bead is formed on the backing material. It is desirable to provide grooves for welding along the welding line. As a welding means, TIG welding, MIG welding, plasma welding, laser welding or any other appropriate welding method is adopted according to the hoop material to be connected.

[0007]

As described above, in the conventional method of connecting hoop materials, a phenomenon in which the molten pool melts down at both ends 3S and 3E of the butt weld line 3 of both hoop materials easily occurs. This is because both ends 3S and 3E are discontinuous portions between the hoop material and the tab material, and an air layer interposed between the two members prevents heat from being dissipated by welding, so that heat is discontinued at the discontinuous portions. This is because the accumulated temperature becomes high and the molten pool cannot be supported. That is, when the molten pool shifts from one tub material 4 to the end 3S, the end of the tub material 4 is first heated to a high temperature and melts down, and the molten pool cannot be supported. End 3S melts off. A similar state is exhibited at the other end 3E.

In view of such a situation, the present inventors have conducted an experimental study and found that, in order to dissipate heat, the point of contact between the butt welding line of both hoop materials and the tab material was formed by arc spot welding. The present inventors have completed the present invention by concluding that tack welding is effective. That is, as shown in FIG. 1, the butt welding line 3 of both hoop materials 1 and 2 to be connected and the contact point of the tab materials 4 and 5, ie, the starting end 3S and the ending portion 3E of the butt welding line 3 are formed by arc spot welding. By performing tack welding A and B, the hoop material and the tab material are bridged at this portion, and from the tab material 4 side to the hoop materials 1 and 2 through the tack welding portions A and B, which are bridging portions. Further, heat is dissipated from the hoop materials 1 and 2 to the tab material 5 side to avoid heat accumulation. That is, when welding is started from the S point of one tab material 4 and the welding progresses to the starting end 3S of the butt welding line 3, the welding heat is actively transmitted from the tab material 4 side through the temporary welding portion A. Lumber 1, 2
Because of the escape to the side, the part does not locally become hot, thus avoiding burn through of the molten pool.
Similarly, when welding has progressed to the terminal end 3E of the butt welding line 3, the welding heat actively escapes from the hoop materials 1 and 2 to the tab material 5 through the temporary welding portion B. The temperature does not rise. Therefore, burn-through of the molten pool is avoided, and the welding proceeds satisfactorily and ends when it reaches point E of the other tab material 5.

[0009]

EXAMPLES In order to confirm the effect of the present invention, connection of hoop materials was carried out under the following conditions in the manner shown in FIGS. (1) Test hoop material: Material SPHC steel strip Dimensions Thickness 2.2 mm, width 62.9 mm (2) Tab material: Material SPHC steel plate, thickness 2.2 mm (3) Welding conditions Groove: groove gap 0 mm I groove backing strip of: grooved copper plate welding method: tack welds a by TIG welding without filler metal, B performs arc spot Tsu preparative welding, E point from point S including butt weld line 3 This welding was performed on one side only. TIG welding conditions Electrode rod diameter: 2.3 mm Distance between electrode rod and base material (hoop material): 1.5 mm Polarity: DCSP (DC positive polarity) Shielding gas: Ar gas, flow rate 10 l / min Current: arc spot welding 100 A Main welding 200A Welding speed: Temporary welding 0mm / min Main welding 250mm / min As a result of connecting hoop material 1 and hoop material 2 under the above conditions, the molten pool does not melt off at both ends 3S and 3E of butt welding line 3. From the tab material 4 to the butt welding line 3,
Also, the transition from the butt welding line 3 to the tab material 5 was excellent.
Of course, the main weld was good in both front and back beads. After the welding was completed, the tab members 4 and 5 were cut off, and the side surfaces were aligned with the hoop edge surface. After the connection of the hoop material, this hoop material was applied to the production of a flux-cored seamless wire for welding. Since there was no welding defect at the connection portion of the hoop material as in the prior art, the outer diameter of the pipe was about 20 mm and the product diameter was 1.
It was able to withstand a diameter reduction of up to 2 mm sufficiently, and there was no disconnection at the connection part of the hoop material. That is, the hoop material after connection was gradually formed from a U-shape to an O-shape by a forming roll. During the molding, a flux (main component: rutile) was supplied to the hoop valley at a filling rate of 12% by a feeder from an opening along the longitudinal direction of the U-shaped hoop material. Then, at the same time high-frequency induction welding opposing edge surface of the opening when molded into O-shape (heat input E _P I _P = 140kVA, frequency = 520 kHz, welding speed 30 m / min) tube outside diameter continuously butt welding by A 20 mm flux-filled tube was used. Then, the outer diameter was reduced to 12.5 mm by a rolling roll group and wound up in a coil shape. Next, after the coil was annealed, in a separate drawing process, the product was drawn to a product diameter of 1.2 mm at a final drawing speed of 1000 m / min using 33 dies. When 10 tons of the hoop material after the above connection (the connection portion: 9 places) was applied to the production of the flux cored wire for welding, it was possible to sufficiently withstand a reduction in diameter to a product diameter of 1.2 mm, and the connection portion of the hoop material Did not cause any disconnection.

[0010]

According to the present invention, in the connection between hoop materials for powdered wires, welding can be performed at both ends of the butt welding line without causing the molten pool to burn through. Since there is no welding defect at the connection between the hoop materials,
When a powder-containing wire is manufactured using this hoop material, it can sufficiently withstand reduction in diameter to the product diameter.

[Brief description of the drawings]

FIG. 1 is a plan view showing a point of connection between hoop materials.

FIG. 2 is a side view of FIG.

[Explanation of symbols]

 1, 2 Hoop material 3 Butt weld line 4, 5 Tab material A, B Temporary weld at both ends of butt weld line

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-61-180699 (JP, A) JP-A-47-33039 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B23K 35/40 B23K 9/02 B23K 9/235 B23K 37/06

Claims (1)

(57) [Claims] 1. A method for connecting the hoop material used for the outer powder-cored wire filled with powder to be metal tube, the tab member end face
Tab material so that it touches the side of the hoop material
A hoop material for powdered wire , which is disposed on both sides of the hoop material , and the contact point between the butt welding line and the end face of the tab material is tack-welded by arc spot welding , and then the butt welding line is welded on one side. Connection method.