IMPROVEMENT OF RESIDUAL STRESS ON GUSSET WELDED JOINTS BY HEAT TREATMENT WITH INDUCTION HEATING
May Phyo AUNG 1*, Mikihito HIROHATA 2 and Yasuo KITANE 1
1 Department of Civil and Environmental Engineering, Nagoya University, Nagoya, Japan
2 Department of Civil Engineering, Osaka University, Osaka, Japan
Residual stress induced by welding process is one of the dominant factors which deteriorate the fatigue performance of the welded steel structures. In order to investigate the improvement of the residual stress state in the welded steel joints, a series of experiment and numerical simulation were conducted on gusset welded joints by applying heat treatment with induction heating (IH). In this study, a new finding of a heating condition comprising target temperature, heating field size, and heating field position, which would alleviate or eliminate the welding-induced tensile residual stress near the weld toe, was developed. It was observed that heat treatment with IH could accurately control the target temperature. The proposed heating condition could improve the residual stress state by means of reducing the welding-induced tensile residual stresses to almost zero near the weld toe after superimposing the compressive residual stresses. Therefore, it is anticipated that the proposed heating condition could be applied for improvement of the fatigue performance of the gusset welded joints.
Residual stress; Welding; Heat treatment; Induction heating; Thermal elastic-plastic analysis; Fatigue performance