Research of temperature and microstructure in friction stir welding of Q235 steel with laser-assisted heating

Abstract

In this paper, a three dimension heat source is developed in laser heated friction stir welding. The model was calculated by CFD software FLUENT, and the temperature field and flow field of the welding are obtained. The effect of absence or presence of laser beam on flow field and temperature field is discussed. The microstructure of nugget zone between laser assisted friction stir welding and traditional friction stir welding is analyzed by metallographic observation. Results show that welding quality will be improved if it is used laser assisted friction stir welding to weld Q235 steel plates instead of traditional friction stir welding. Keywords: Laser-heated, Friction stir welding, Thermal model, Temperature, Microstructure