Numerical simulation of 3-D flow field on laser-assisted heating friction stir welding of steel

In order to optimize welding parameters of laser-heated friction stir welding (FSW) and provide theoretical foundation for experiments, numerical simulation was adopted and simulation of 3-D flow field of Q235 steel laser-assisted heating FSW was conducted. Flow behavior and heat transfer process ofviscoplastic material were analyzed. Flow field and temperature distribution of welding material were acquired.The results show that the welding material is transported mainly along the retreating side.When rotational speed increases from 750r/min to 1180r/min under the condition of 800W laser power and 23.5mm/min welding speed, the material flow gets stronger. The highest temperature rises, but not more than the melting point of steel. The phenomenon is consistent with that the steel does not melt in the process of the actual experiment. Laser, as an auxiliary heat source,can provide heat input during the welding process and can improve mobility of welding materials.