Experimental and Numerical Investigation of Trailing Heat Sink Effect on Weld Residual Stress and Distortion of Austenitic Stainless Steel

摘要

In this study, welding with a trailing heat sink was applied to austenitic stainless steel for reducing the weld residual stress and distortion. The effects on temperature profiles, residual stress and distortion were experimentally investigated through the use of gas tungsten arc welding with and without a water-cooling device. As the results, the weld residual stress and distortion can be reduced without affecting the weld penetration by welding with a trailing heat sink. Numerical investigation was also performed using the three-dimensional thermal elastic-plastic finite element analysis. A numerical model of gas tungsten arc welding was constructed based on the physics of the welding arc. The calculated weld penetration, temperature profiles, residual stress and distortion were in good agreement with those measured under the same welding conditions. Using the simplified model of homogeneously distributed heat sink on the basis of the developed welding simulation, the effect of intensity of the heat sink on the weld residual stress and distortion was quantified. Furthermore, the mechanism of the reduction of weld residual stress and distortion was discussed based on the temperature distribution variation in welding with a trailing heat sink. Based on the results, the effectiveness of welding with a trailing heat sink in reducing the weld residual stress and distortion of austenitic stainless steel has been clarified.