METHOD OF CONTROLLING WELD COMPLETION AT REPEAT- OPERATION IN TIG WELDING

摘要

PROBLEM TO BE SOLVED: To provide a method that controls weld completion at a repeat- operation in a tungsten-electrode inert gas (TIG) welding, which can prevent the generation of welding defects such as a crater crack, a blow hole, or a burnt-through, in a crater part and prevent the deterioration of welding quality caused by the positional dislocation of the weld completion.;SOLUTION: When a torch switch becomes closed at starting of welding, application of initial current Is is started. Thereafter, when the torch switch becomes open, the current is switched to welding current Iw. Thereafter, when the torch switch changes into an open state after being kept in a closed state during the time less than the operation determining time Td previously given, the welding current Iw is switched to a crater current Ic or inversely the crater current Ic is switched to the welding current Iw. When the torch switch changes into an open state after being kept in a closed state beyond the operation determining time Td during the period that the welding current Iw or the crater current Ic is applied, the application of current is stopped to complete the welding.;COPYRIGHT: (C)2003,JPO