Study on prevention of angular distortion in fillet welded T-joint by welding with a trailing reverse-side gas heating

Reduction or control of angular distortion without additional processes is demanded because it takes great time and effort to correct the angular distortion of fillet welded T-joint. In this study, the reduction or control of angular distortion of both sides fillet welded T-joint by welding with a trailing reverse-side gas heating was investigated through the welding experiment and its numerical simulation. First, the effect of gas heating position and intensity on the reduction of angular distortion was experimentally investigated using gas burner. As the results, angular distortion became the smallest when the reverse-side heating using gas burner was located at backward 50mm of the welding torch. Also, the concentrated gas flame with increased propane and oxygen gas flow was effective for reducing angular distortion. It was clarified that the angular distortion could be controlled completely with an appropriate reverse-side gas heating condition. Next, the numerical simulation model of welding and gas heating was constructed based on comparison with the measured temperature histories and angular distortion. Through the numerical simulation of welding with a trailing reverse-side gas, more detailed understanding on the effect of gas heating condition on reduction of angular distortion was developed. In addition, it was confirmed that the gas heating position for the smallest angular distortion is dependent on the temperature distribution along thickness of flange plate. © 2014, Japan Welding Society. All rights reserved.