An Optimized Heat Treatment Process to Reduce the Weld Residual Stress by Auxiliary Heating

Abstract

Local post welding heat treatment (PWHT) is a popular method to reduce the residual stress of bigger weld structures. In this paper, the weld residual stresses before and after local PWHT were investigated. The results show that there are larger axial stresses concentration in weld toe and an inconsistent deformation along axial direction during heating stage which may leads to crack. The residual stresses in outer surface are decreased greatly after local PWHT. An optimized local PWHT with auxiliary heating (AH) temperature 800°C and width 800mm were proposed. The axial stress and deformation inconsistent in weld can be reduced by AH, thus leads to the reduction of crack risk in weld toe.