Effect of Oxide Fluxes in Activated TIG Welding of Stainless Steel 316LN to Low Activation Ferritic/Martensitic Steel (LAFM) Dissimilar Combination

The aim of current work is to study the effect of different oxide fluxes in activated TIG welding process of dissimilar welding between LAFM and 316LN on weld dimensions, macro- and microexamination, and microhardness. Different oxide fluxes, namely TiO2, Fe2O3, CuO, Co3O4, and HgO, were used for the experiment, and its results were compared with convention TIG welding. Flux paste was applied over the area to be welded using a paint brush at the middle portion of the specimen. All welding experiments were carried out on a bead on a plate and under the same welding conditions and parameters. The experimental result reveals that full-length penetration was achieved with the use of Co3O4 and TiO2 fluxes. This enhancement in depth of penetration is attributed to the reverse Marangoni effect and arc constriction mechanism. In this study, insight was also revealed pertaining to the depth-enhancing mechanism present during ATIG welding of LAFM and SS316LN joints.