Welding of 304L Stainless Steel with Activated Tungsten Inert Gas Process (A-TIG)

Gas tungsten arc welding is a popular process in those applications requiring a high degree of quality and accuracy. However, this process has a big disadvantage against the substantially high productivity welding procedures. Hence, many efforts have been made to improve its productivity. One of these efforts is the use of activating flux (A-TIG welding). In this study, the performance of A-TIG welding on 304L austenitic stainless steel plates has been presented. Two oxide fluxes, TiO2 and SiO2 were used to investigate the effect of A-TIG welding process on weld morphology, microstructure and mechanical properties of weldments. The experimental results indicated that A-TIG welding could increase the weld penetration and depth-to-wide ratio. It was also found that A-TIG welding could increase the delta-ferrite content of weld metals and improve the mechanical properties. Moreover, a 2D axial symmetric model was developed to simulate the flow behavior in the melting pool. These results were compared to those experiments carried out on a stainless steel (304L) melted by a stationary heat source.