Performance analysis of various fluxes in different variants of the TIG welding process on the quality of welding

The tungsten inert gas (TIG) welding process is widely used in various industries for its ability to produce high-quality welds at a low cost. However, TIG welding struggles with welding thick stainless steel in a single pass, reducing production efficiency. To address this, new TIG variants such as activated TIG (A-TIG), flux bound TIG (FB-TIG), and flux zone TIG (FZ-TIG) have been developed to enhance penetration in austenitic stainless steel. This study investigates the effects of TiO2 and Fe2O3 flux on 304 stainless steels welded using A-TIG, FB-TIG, and FZ-TIG processes. Results show a slight increase in the depth-to-width (d/w) ratio for A-TIG and FB-TIG, while FZ-TIG achieved a 59% higher d/w ratio compared to autogenous TIG welding. The increased penetration is attributed to the reversal Marangoni convection and arc constriction. Microstructural analysis reveals a higher delta ferrite content in A-TIG and FZ-TIG welds due to increased heat input. Additionally, FZ-TIG welds exhibited an 11.5% higher microhardness compared to autogenous TIG welds. FZ-TIG welding enhances penetration and mechanical properties effectively.