Reducing Full-Field Residual Stress of Girth Weld With Thick Wall by Combining Local PWHT and Water Jet Peening

Abstract

In this paper, a new controlling method combined local postweld heat treatment (PWHT) and water jet peening (WJP) was proposed to reduce full-field residual stress of girth weld with thick wall. The finite element analysis with sequential coupling method and experiment measurement were performed to study the residual stresses distribution before and after the new controlling method. The results show that the hoop and axial stresses through the thickness are all decreased greatly by using the new controlling method. As long as the new controlling method is used with appropriate parameters, the residual stresses on inner surface can be reduced from tensile stresses to compressive stresses, which greatly improve the resistance ability to stress corrosion of inner surface.