Microstructure and properties of weld by high-speed tandem TIG welding of different arc power matching

The experimental materials were 304 austenite stainless steel plates, with 1.2 mm in thickness. According to the analysis of the weld appearance, and the microstructures and properties of the weld joint, the quality of the weld beads at different parameters was obtained. The experimental results show that the average grain size at higher leading arc power of weld center is about 33.9% lower than that of the base metal. Meanwhile, the average grain size of HAZ is reduced by about 18.1% compared with higher rear arc power. The tensile strength of the weld is higher than that of the standard specimens with higher rear arc power, by 7.9%, and the elongation is higher than that of higher rear arc power, by 33.3%. It indicates that the weld at higher leading arc power behaves better properties.