This study addressed the use of activated flux SiO2 for the gas tungsten arc (GTA) welding of super-austenitic stainless steel plates of 5 mm thickness. Trials were carried out to investigate the effect of flux and the welding current to determine the depth of penetration. Bead-on-plate trials were carried out on the AISI 904L with and without flux. It was inferred from the macrostructure studies that with a welding current of 180 A, complete penetration could be achieved using flux-assisted GTA welding. The optimal process parameters were validated by conducting the experimental investigations to ascertain the structure–property relationships of flux-assisted GTA weldment. Experimental results corroborated that the average tensile strength and impact toughness of SiO2 flux-assisted GTA weldments of AISI 904L were observed as 553 MPa and 49.3 J. It was inferred from the studies that defect-free welds of super-austenitic stainless steel could be obtained on employing flux-assisted GTA welding process. © 2015, Springer-Verlag London.