Determination and Validation of Residual Stresses by X-Ray Diffraction Method of Pipe Girth Weld Joint

Abstract

During welding the stresses are induced after the cooling and this induced residual stresses affects the life of the weld joint. In this paper we find out the residual stresses induced in the carbon steel pipe and validate the result by experimental analysis and suggest the method of relaxation by post weld heat treatment. This paper explored the residual stresses in ASTM A53 (Grade B) pipe girth welds, before and  after post weld heat treatment by Xray diffraction method which includes full residual stress mapping in the weldment and close to external and internal pipe surface. The induced residual stresses simulated by thermomechanical analysis. The results compared and validated to recommend the PWHT is effective to reduce the residual stresses.