Effect of Manual and Automatic Activated Tungsten Inert Gas Welding Using Single Component Fluxes on Stainless Steel AISI-304

Abstract

The study compared the effects of manual activated tungsten inert gas (A-TIG) welding and automated A-TIG welding on AISI (American Iron and Steel Institute)- 304 at three different values of current using commercially available powders of Al2O3, SiO2, Fe2O3, MgCl2, and TiO2 separately as activated flux and distilled water as carrier solvent. The effect of fluxes on the depth of penetration of the weldments, width of weldment, microstructure of the weldment, and microhardness of the weldment was investigated. Reverse Marangoni convection and arc constriction are found to be more effective in A-TIG manual welding, as aspect ratio obtained by A-TIG manual welding is greater as than that of automatic A-TIG welding. Microstructure of both the manual and automatic A-TIG-welded specimen is similar with no noticeable differences and almost same amount of intermetallic phases and carbon precipitates. Microhardness tests revealed that for Al2O3 and TiO2 fluxes, manual A-TIG-welded specimen have lower values of microhardness at weldment, heat-affected zone, and base metal than automated A-TIG-welded specimen. The aim of the study is to implement the manual A-TIG process in shipbuilding industry to improve the productivity of welding as automated A-TIG welding in the industry has limitations.