Practical Investigation of Weldment of FSS (AISI 430) Welded by TIG Welding Process

Ferritic stainless steel is generally considered to have poor weldability when compared to austenitic stainless steel but has recently drawn greater attention owing to their lower costs and better resistance to stress corrosion resistance than austenitic stainless steel. It has excellent performance of chloride stress corrosion and spot corrosion resistance addition to excellent strength. This work reports the microstructural and mechanical behaviour of AISI 430 FSS weldments welded by TIG welding using austenitic filler wire (ER309L) and ferritic filler wire (ER430). In case of austenitic filler wire very fine austenitic grain was formed in fusion zone (FZ). In case of ferritic stainless steel filler wire, the microstructure of the fusion zone and the heat affected zone shows coarse inter dendritic structure which was greatly influenced by rapid grain growth. The mechanical properties of the weldment was also evaluated and correlated with microstructure. During the tensile test the specimen was broken outside the welded joint (in base metal) which confirms the good quality of the joint. It was observed that the joints produced by TIG welding exhibit superior impact properties compared to the base metal.