Correction of Butt-Welding induced Distortion by Laser Forming

Welding-induced distortion is an intrinsic problem arising due to the mismatch of thermal expansions in the weld and surrounding material. The distortion can be minimized through the pre-process, in process, or post-process methodology. In the present paper, the laser forming (LF) technology is utilized for the post correction of the welding-induced distortion. Three types of weld paths are applied on the bead-on-plate welding. The induced out-of-plane distortion can be divided into angular distortion and longitudinal distortion. The LF correction paths are determined based on the magnitude and direction of bending angle and the longitudinal residual stresses. The corresponding heating conditions are determined through the heating database established by finite element method (FEM) simulations. Through the experimental validation, it is found that the proposed laser forming strategies can reduce not only the welding-induced distortion, but also the tensile longitudinal residual stress on the welded surface. It is concluded that the laser forming process is effective to reduce the welding induced distortion.