MIG WELDING METHOD AND MIG WELDING DEVICE

摘要

In the present invention a first operation and a second operation are repeated. In the first operation a pair of weld wires 22, 24 the current value of which can be changed individually are arranged along a bevel 1a of steel plates 1, 1 and a current of approximately the same current value is supplied to the weld wires 22, 24, thereby generating a cathode spot toward the front of the weld pool with the arc of the weld wire 24 on the advance side in the welding direction, and cleaning the surfaces of the steel plates 1, 1 by means of the arc. In the second operation a pulse current having a higher current value than that of the weld wire 24 is supplied to the weld wire 22, thereby generating a cathode spot in the weld pool with the arcs of both weld wires 22, 24 and again forming the weld pool, and welding is carried out in the area in which oxides have been removed from the surfaces of the steel plates 1, 1 while both weld wires 22, 24 are moved forward in the welding direction and the cathode spot is moved to the new weld pool. Thus, it is possible to stabilize the arc without requiring a high current, and to carry out low-cost and high-quality welding with high efficiency.