ARC SPOT WELDING METHOD OF LINING MATERIAL BY TWO-STAGE CHANGE-OVER OF CURRENT

摘要

PURPOSE:To reduce execution time and to perform spot welding of a lining material without uneven quality by changing over currenet and performing arc discharge by weak current for specified time after arc spot welding by strong currnet. CONSTITUTION:A lining material 10 is placed on a base metal 9 and an arc torch 2 is placed to face said metal. The tip of a wire is brought into contact with the material 10 and spot welding of the material 10 is started by passing strong current. The welding current is changed over to weak current with a control device 5 according to a timer 6 after set time and at the same time the feed speed and voltage of a wire 7 are changed over. Arc discharge is performed only for the set time by the weak current to prevent quick cooling of the weld zone. The supply of the welding current and the feed of the wire 7 are further stopped upon lapse of the specified time. The always stable weld result is obtd. by the above-mentioned method without defects such as a weld crack.