Effects of oxide-based flux mixtures on the dissimilar A-TIG welding of carbon steel to stainless steel

摘要

The objective of the present investigation was to study the effects of oxide-based flux mixtures on the surface appearances and weld bead profiles of activated tungsten inert gas (A-TIG) welds. The A-TIG welds (oxide fluxes) were carried out on 6 mm thick dissimilar welds between carbon steel (SA 516 grade 70) and austenitic stainless steel (SS304). TiO_2, ZnO and MnO_2 oxide-based fluxes were selected for the investigation. Experiments were carried out using the GTAW electrode diameter (3.0 mm) and the joint gap was also selected as one of the variables. The depth of penetration (DOP) value increases with the mixture of fluxes. The highest depth-to-width ratio (D/W) was reported under the ZnO and MnO_2 flux mixtures compared to the normal TIG. When the torch position is in line with SS, the TiO_2 flux achieves the highest penetration compared to the ZnO flux.