The effect of pulsed GTA welding on the residual stress of a stainless steel weldment

The objective of this study was to investigate the effect of pulsed GTA welding parameters on the residual stress of the weldment. Autogenous gas tungsten arc welding was applied on SUS 304 and SUS 310 stainless steels to produce a bead-on-plate weld. The residual stress was determined by using the hole-drilling strain-gage method of ASTM standard E837. The experimental results show that a greater pulse frequency, a larger pulse spacing, a greater amplitude ratio, and a greater duration ratio can reduce the magnitude of the residual stress in the austenitic stainless steel weldment. The residual stress of the 310 stainless steel weldment is greater than that of the 304 stainless steel weldment under the same welding conditions because of its lower thermal conductivity and thermal diffusivity. The experimental results also showed that pulsed current welding has a smaller range of the tensile residual stress zone as compared to that of constant current welding because of its lesser amount of heat input.