The Effect of TIG Welding Heat Input on the Deformation of a Thin Bending Plate and Its Weld Zone

Abstract

Heat input is a crucial parameter in the process of welding thin plates. It has a direct impact on the quality of the weld and the degree of deformation caused during welding. This study investigates the impact of heat input on the deformation of a thin bending plate and its weld zone using the thermoelastic–plastic finite element method. The accuracy of the model is ascertained using the non-contact inspection method utilizing digital image correlation technology. The welding deformation patterns of thin bending plates with a radius of 500 mm were analyzed at various welding heat inputs ranging from 173 J/mm to 435 J/mm. The results indicate that the finite element prediction model proposed in this paper is highly accurate. It has been observed that, under this range of thermal input, the thin bent plates undergo saddle deformation. By examining the correlation between heat input and the maximum deformation outside of the plane, it has been determined that a heat input of at least 50 J/mm is required for the thin bending plate to experience out-of-plane deformation. Additionally, as the level of heat input increases, so too does the out-of-plane deformation of the thin bending plate. After the completion of the welding cooling process, the transverse shrinkage at the weld seam of the thin bend plate is twice that of the longitudinal shrinkage. However, the transverse deformation of the bend plate is not significantly different from the longitudinal deformation.