| 摘要 |
PURPOSE:To prevent the precedence burn-through, internal defect, etc. of a molten metal and to improve wettability by disposing filler wires before and behind a TIG welding electrode, and performing welding while feeding alternately and continuously the respective wires. CONSTITUTION:Filler wires 3, 4 are disposed respectively in a V shape before and behind a TIG welding electrode 2 extended from a head 1 of a welding carriage, and while the front wire 3 and the rear wire 4 are alternately and continuously fed, a tubular base material is welded under rotation. The feed of the wire 3 is stopped before the preceding burn-through of the molten metal by the wire 3 rises in a vertical down part of all attitudes welding. The feed of the wire 4 is stopped before the internal defect by dragging of the wire 4 arises, whereby the beads having an improved fitness and high reliability are obtd. The feed of the wires 3, 4 is similarly adjusted in a vertical up part as well, whereby satisfactory welding is accomplished. |
