Investigation of the E ect of Clamping on Residual Stresses and Distortions in Butt-Welded Plates

Abstract

One major disadvantage of many arc welding processes is welding-induced residual stresses and distortions. The non-uniform heating and cooling during arc welding result in non-uniform expansion and contraction of the weld and surrounding base material, which produces undesirable residual stresses and deformations in the welded joint. A number of methods can be used to control welding-induced distortions. The methods used for controlling welding distortions a ect residual stresses and vice versa. One practical method for minimizing welding angular distortions is the use of clamping. In this paper, the e ect of clamping and clamp releasing time on welding residual stresses and distortions in the single-pass butt welding of 304 stainless steel plates are investigated. Cases with and without clamping have been studied, and residual stresses and angular distortions have been predicted by three-dimensional nite element simulation. Moreover, experiments have been carried out to measure temperature histories, angular distortions and residual stresses for the unclamped case to verify the numerical model. The results of this study revealed that clamping and clamp release time have a great in uence on the distribution of residual stresses and nal angular distortions. Using clamping during welding and releasing after cooling to ambient temperature can signi cantly reduce the amount of nal angular distortions.