Magnetism aided mitigation of deformation and residual stress in dissimilar joint 316L with EH36

Abstract

Magnetism aided mitigation of deformation and residual stress was researched in dissimilar joint 316 L with EH36. Application of external magnetic field, microstructure was refined, weld profile was regulated by narrowing upper width and broadening bottom width. A simulation method by integrating image extraction and fitting of actual weld profile into thermal elastic plastic finite element analysis was proposed to evaluate welding deformation and residual stress in the dissimilar joint with an asymmetrical weld shape. Considering the effect of external magnetic field, welding deformation was decreased by ∼34%, the tensile stress was reduced. Mitigation mechanism by external magnetic field was that temperature gradient and cooling rate of the weld pool were decreased by Lorentz force stir with low micro-strain and micro-stress. This work offered an effective method to regulate deformation and residual stress of dissimilar joint in laser welding.