Experimental and numerical investigation into effect of weld configuration geometry on distribution of residual stress and temperature in the welded parts of stainless steel

Abstract

In multi-pass grooved welding, residual stress and corresponding distortion are highly affected by welding process parameters, material properties, and fixture design. Therefore, having knowledge about value of the residual stress and transient temperature yields long life joints with high dimensional accuracy. In the present study, three joints with different T-joint configurations made of 316 stainless steel were fabricated through gas tungsten arc welding process. The first configuration includes single bevel without root face and gap, the second includes single bevel with root face and 1 mm gap, and the third includes double bevels with root face and 1 mm gap. In order to evaluate temperature and residual stress distribution, finite element simulation of aforementioned process using SIMUFACT WELDING software along with hole-drilling method (as semi-destructive evaluation) and ultrasonic method (as non-destructive evaluation) were performed. Also, thermal history of welding process was recorded by K-type thermocouple. Research findings showed that the thermal history and residual stress distribution which were obtained through FE simulation are in high agreement with those derived from both ultrasonic and hole-drilling methods. Furthermore, the change in joint configuration significantly affects transverse residual stress but it has not great impact on longitudinal residual stress. Also, the highest and lowest residual stress and corresponding distortion are for the first and third configurations, respectively.