Numerical investigation on residual stress distribution and evolution during multipass narrow gap welding of thick-walled stainless steel pipes

The detailed pass-by-pass finite element (FE) simulation is presented to investigate the residual stresses in narrow gap multipass welding of pipes with a wall thickness of 70 mm and 73 weld passes. The simulated residual stress on the outer surface is validated with the experimental one. The distribution and evolution of the through-wall residual stresses are demonstrated. The investigated results show that the residual stresses on the outer and inner surfaces are tensile in the weld zone and its vicinity. The through-wall axial residual stresses at the weld center line and the HAZ line demonstrate a distribution of bending type. The through-wall hoop residual stress within the weld is mostly tensile. After the groove is filled to a certain height, the peak tensile stresses and the stress distribution patterns for both axial and hoop stresses remain almost unchanged. (C) 2011 Elsevier B.V. All rights reserved.