TREATMENT OF BEAD END IN TIG WELDING

摘要

PURPOSE:To decrease the mending of a bead end and to prevent the shrinkage crack thereof by running a torch at a constant speed to the terminal of a weld line, stopping the torch and decreasing and interrupting the welding current in said position. CONSTITUTION:The torch 3 is run at the constant speed to the end of the bead 2 and is stopped. The welding current is gradually decreased to a prescribed value and is interrupted while the position is maintained. The decrease of the welding current is started upon stopping of the torch 3 and therefore the arc length is adequately maintained and the heat energy of the arc to the bead end is gently and continuously supplied. The flow down of the molten metal at the bead end is thus obviated and the sag is prevented. The mending is decreased and the bead end is preheated by the above-mentioned method and therefore the shrinkage crank is prevented.