Study on heat-affected zone of TWIP steel after welding

In this paper,microstructure and mechanical properties were analyzed on the heat-affected zone (HAZ) of the sheets obtained by applying laser beam and TIG welding. The result shows that microstructure of HAZ and fusion zone (FZ) becomes finer and distributes more uniformly and the elongation is significantly better than that of TIG welding. Microhardness of FZ is larger than that of the base metal. Grains of TIG welding in HAZ grow a lot,and microhardness is significantly reduced in the HAZ which leads to worse comprehensive performance.