JPH1024368A - Magnetic agitation welding method and equipment therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To micronize the structure at solidification of molten metal by generating a magnetic field by causing AC to flow to a magnetic coil around a welding torch and agitating molten metal with crossing magnetic field to molten pool through a cylindrical iron core. SOLUTION: The magnetic welding equipment is arranged with a welding torch 1 which generates arc by supplying welding current, shield gas, wire to generate molten pool, a magnetic coil 2 which generates a magnetic field around the welding torch 1 by supplying AC, a cylindrical iron core 3 which agitates molten metal with crossing magnetic field to molten pool and a cooling means 4 to cool the magnetic coil 2. By this method, the structure of molten metal is micronized, generation of defect in weld zone is reduced, the mechanical property is improved as well.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic stir welding method and apparatus, and more particularly to a technique for performing welding while stirring a molten metal by applying a magnetic field to a molten pool.

[0002]

2. Description of the Related Art As a technique relating to a magnetic stir welding method, for example, Japanese Patent Application Laid-Open No. 04-190975 entitled "Magnetic Stir Welding Method and Magnetic Stir Welding Apparatus" has been proposed. In this technique, as a magnetic stir welding method, a magnetic coil is provided so as to surround the welding torch, and an arc is generated using a direct current with the electrode of the welding torch as a negative electrode, while the magnetic coil applies a magnetic field to the molten pool. To stir the molten metal.

[0003]

However, in the above technique, although the magnetic flux density in the vicinity of the magnetic coil increases, the magnetic flux density crossing the molten metal does not always become sufficiently large. It is necessary to bring the magnetic coil close to the molten metal, and therefore, there remains a problem to be solved such that the magnetic coil is easily heated by welding heat.

[0004] The present invention is to epoch-makingly solve such problems of the prior art, (1) to make the structure finer during solidification of the molten metal in a stable state, (2).
The purpose of the present invention is to reduce the occurrence of defects in a welded portion and improve mechanical properties, and (3) to facilitate cooling of a magnetic coil.

[0005]

A welding current is applied to a welding torch.
A step of supplying a shielding gas and a wire to generate an arc to generate a molten pool; a step of supplying an alternating current to a magnetic coil around a welding torch to generate a magnetic field; and melting the magnetic field through a cylindrical iron core. The step of crossing the pond and stirring the molten metal performs the welding operation. And
The diameter of the cylindrical iron core is set according to the size of the molten pool, and the magnetic coil is provided with cooling means for cooling. Further, the welding device is provided with control means, the control means being electrically connected to the welding torch and controlling a welding power supply and a supply of a shielding gas, and a welding power supply control unit, and electrically connected to the magnetic coil. It comprises a magnetic coil control unit for controlling an alternating current from a power supply, and a main controller for controlling the circulation of cooling water supplied via a cooling water supply system.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a magnetic stir welding method and apparatus according to the present invention will be described below with reference to FIGS. 1 to 3,
1 is a welding torch, 2 is a magnetic coil, 3 is an iron core, 4 is a cooling means, 5 is a cooling water supply system, A is a magnetic field, B is a molten pool, C is a base material, and D is a welding bead.

First, the magnetic stir welding apparatus will be described. The magnetic welding apparatus generates an arc by supplying a welding current, a shield gas and a wire, and a welding torch 1 for generating a molten pool, and a supply of an AC current. A magnetic coil 2 for generating a magnetic field A around the welding torch 1, a cylindrical iron core 3 for stirring the molten metal by crossing the magnetic field A to the molten pool B, and a cooling means 4 for cooling the magnetic coil 2 Have.

The iron core 3 is detachably fixed around the welding torch 1 with bolts or the like. When an alternating current is supplied to the magnetic coil 2, the iron core 3 has a cylindrical shape as shown in FIG. A high-density magnetic field A is generated near the end face.

Since the magnetic field A has a large magnetic flux density near the end face of the iron core 3, if the diameter of the cylindrical portion of the iron core 3 is adjusted to the size of the molten pool B, the magnetic field A Are concentrated and a large stirring force is generated. Therefore, as the welding operation proceeds, the molten metal in the molten pool B solidifies (solidifies), whereby the weld beads D are sequentially formed on the base material C. However, sufficient stirring is performed at the peripheral edge of the molten pool B. The welded portion D becomes the weld bead, and the structure can be refined.

As shown in FIG. 2, the cooling means 4 is a water-cooled jacket having a hollow portion. The cooling means 4 is provided with a cooling water supply system 5 through a pipe 6 and an inlet 4a. After cooling water is supplied to the inside to cool the magnetic coil 2, the cooling water is returned to the cooling water supply system 5 via the outlet 4 b and the pipe 6.

In FIG. 1, reference numeral 10 denotes control means, which includes a magnetic coil control unit 11, a welding power supply control unit 12,
And a main controller 13. Then, the magnetic coil control unit 11 is connected to the magnetic coil 2,
An alternating current is controlled. The welding power supply controller 12 controls the welding current supplied to the welding torch 1 via the welding machine 14, and the main controller 13 controls the welding current via the cooling water supply system 5. Thus, the amount of cooling water supplied to the cooling water 4 is controlled.

In the present invention, a technique of using a water-cooled tube serving also as the magnetic coil 2 as the cooling means 4 and winding it around the iron core 3 can be adopted.

[0013]

The magnetic stir welding method and apparatus according to the present invention have the following effects. (1) An alternating current is passed through a magnetic coil around a welding torch to generate a magnetic field, and the magnetic field is caused to cross the molten pool through a cylindrical iron core. By sufficiently stirring, the structure of the molten metal can be refined during solidification. (2) The agitation of the periphery of the molten pool is promoted based on the cylindrical shape of the iron core, and a weld bead is formed by the agitated portion, thereby reducing the occurrence of defects in the welded portion and improving the mechanical properties. Can be improved. (3) By arranging the cooling means around the cylindrical iron core, the cooling of the magnetic coil is facilitated and the welding operation can be performed efficiently. (4) The reliability of the welding operation can be improved by arranging the control means and comprehensively controlling the welding current and the magnetizing current and controlling the cooling water.

[Brief description of the drawings]

FIG. 1 is a front view together with a block diagram showing an embodiment of a magnetic stir welding method and an apparatus therefor according to the present invention.

FIG. 2 is a front sectional view showing a main part of the magnetic stir welding method and the apparatus according to the present invention.

FIG. 3 is a schematic diagram showing a state of generation of a magnetic field by the iron core of FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Welding torch 2 Magnetic coil 3 Iron core 4 Cooling means A Magnetic field B Weld pool

Claims (4)

[Claims] 1. A step of supplying a welding current to a welding torch (1) to generate an arc, a step of supplying an alternating current to a magnetic coil (2) around the welding torch to generate a magnetic field (A), and Into the molten pool (B) via the cylindrical iron core (3)
Agitating the molten metal by intersecting with the magnetic stir welding method. 2. A welding torch (1) for generating an arc by supplying a welding current and a shielding gas and generating a molten pool by supplying a wire, and a magnetic field (A) around the welding torch by supplying an AC current. A magnetic stirring and melting apparatus comprising: a magnetic coil (2) to be generated; and a cylindrical iron core (3) for stirring the molten metal by causing the magnetic field to cross the molten pool (B). 3. The magnetic stir welding apparatus according to claim 2, wherein the diameter of the cylindrical iron core (3) is set according to the size of the molten pool (B). 4. The magnetic stir welding apparatus according to claim 2, wherein cooling means (4) for cooling the magnetic coil (2) is provided.