A Parametric Investigation of the Through-Thickness Residual Stresses in the Thick Weld Plate Considering Back Chipping: Neutron Diffraction and Finite Element Method

Abstract

Neutron diffraction and finite element method were combined to analyze the through-thickness residual stresses in the thick weld plate considering back chipping. Large residual stresses were generated near the surface. Furthermore, the effect of back chipping width, the heat input of the back weld after back chipping, interpass temperature and plate thickness on the residual stresses were conducted by finite element method. The results showed that larger back chipping width could be helpful to decrease the risk of stress corrosion crack. With the decrease of heat input, the stress variation becomes more obvious. The interpass temperature has an obvious effect on the longitudinal residual stresses but little effect on the transverse residual stresses. Nevertheless, the plate thickness has little influence on the residual stress distribution law. Based on the finite element method results, a formula focused on the 10-40 mm thick plates was fitted to calculate residual stresses with the change of depth through thickness, which was verified by neutron diffraction measurement.