Influences Of Groove Type On Welding Residual Stress And Deformation In SUS304 Austenitic Stainless Steel Butt Joints

SUS304 austenitic stainless steel is suitable for meeting various requirements of corrosion resistance, antioxidant, high temperature resistant and cryogenic parts and equipment due to its good comprehensive mechanical properties and processing properties. Therefore, it is widely applied in industrial products.During the welding process, it is inevitably to produce residual stress and distortion because of the non-uniform temperature field. Austenitic stainless steel has relatively large linear expansion coefficient and low thermal conductivity, so it is easy to generate large thermal stresses and deformation. Moreover, the residual stress and deformation produced in welds have negative influences on the static strength, fatigue strength and structural stability and manufacturing precision. Therefore, how to control and reduce the welding residual stress and deformation of the structure is a very hot topic in welding community. With the rapid development of computer technology and computational welding mechanics theory, numerical simulation technologies have been widely used to predict welding residual stress and deformation in practical engineering structures.As a fundamental research, based on ABAQUS software, a computational approach was developed to simulate welding temperature field, residual stress distribution and deformation for SUS304 austenitic stainless steel multi-pass joint with 10 mm thickness. Meanwhile, experiments were carried out to measure welding residual stresses, transverse shrinkage and angular distortion in the butt weld. Through comparing the simulated results with the measured data, it was found that both residual stresses and deformation predicted by the numerical model were in good agreement with the experimental measurements. The influences of groove on welding residual stress and deformation in a SUS304 austenitic stainless steel butt welded joint whose thick plate is 10 mm were investigated by means of both numerical simulation and experiment. To improve the welding process, control and reduce the welding residual stress and deformation to provide theoretical basis.The experimental and simulation results show that the groove shape has prominent influence on the distribution of residual stress and angular distortion: the high tensile longitudinal residual stress distribution and angular distortion of V-groove are significantly larger than those of K-groove and X-groove, and K-groove is slightly larger than X-groove; while the type of groove has small influence on the peak value of longitudinal residual stress.Based on the common FEM software ABAQUS, the thermal elastic plastic finite element method was developed to simulate welding temperature and residual stresses in a SUS304 steel multi-pass butt-welded joint. Based on the simulated results, the influences of work hardening and annealing effect on calculation accuracy of welding residual stress were clarified.