Transient distortion behavior during TIG welding of thin steel plate

Abstract

To examine the generation characteristics of excessive distortions involved with the welding-induced buckling of a thin steel plate, the temperature profiles and distortion behaviors of welded plates during tungsten inert gas (TIG) welding were experimentally measured. Large-deformation thermal elastic–plastic analysis based on arc physics-based heat source modeling was utilized to accurately simulate the thermomechanical behavior of the plate during welding. The calculated and measured temperature profiles and distortion behaviors were compared to validate the developed numerical analysis technique. On the basis of the developed analysis technique, the effect of geometric imperfections on the thermomechanical behavior of welded thin steel plates was further investigated. Both angular and longitudinal bending distortions were found to monotonically increase with increasing heat input because of excessive longitudinal bending distortion and the secondary generation of angular distortion during the cooling process when buckling occurred. The through-thickness gradient of the plastic strain that developed with the transient distortion behavior during welding resulted in excessive angular distortion in the welded thin steel plate. It was concluded that the transient distortion behavior during welding should be taken into consideration to accurately predict and control large welding-induced distortions in thin steel plates.