Study of arc characteristics using varying shielding gas and optimization of activated-tig welding technique for thick AISI 316L(N) plates

Abstract

• In-house developed activated flux for welding of 316L(N) stainless steel. • Identification of optimum shielding gas mixture based on arc stability studies. • Full-depth of penetration in 11 mm thick plate in single pass welding with optimised parameters at reduced heat input. • Joining of 20 mm thick plate by double side A-TIG welding technique. In the present study, type 316L(N) bead-on-plates were welded using Activated-Tungsten Inert Gas (A-TIG) welding process with argon and helium gas at various ratios to evaluate the arc characteristics. The welding process parameters including shielding gas composition were optimized using the design of experiments to join 11 mm thick plate in a single pass. In addition, the A-TIG welding technique using optimized process parameters was developed to weld plates up to 20 mm thickness with significantly reduced heat input. High power density of helium arc shielding leads to constricted arc column that enhances arc efficiency and produces deeper penetration.