A NEW TECHNIQUE FOR REDUCING THE RESIDUAL-STRESS INDUCED BY WELDING IN TYPE-304 STAINLESS-STEEL

Abstract

A new Technique named as ''parallel heat welding'' (PHW) is developed for the reduction of residual stress. It is performed by a pair of parallel heating torches attached to the welding torch on both sides as a movable heat source during welding. Autogenous gas tungsten are welding process was used in type 304 stainless steel. The experimental results showed that the maximum principal residual stress and parallel welding direction stress can be reduced by 21-32 % when the conventional welding(CW) process is replaced by the parallel heat welding process. The elevation of equilibrium temperature during welding process is a main mechanism for the reduction of residual stress in PHW process.