Investigation of Structure Property Relationship of the Dissimilar Weld Between Austenitic Stainless Steel 316L and Duplex Stainless Steel 2205

Abstract

In the present study, the influence of microstructural changes on the mechanical and corrosion properties of the dissimilar weld between austenitic stainless steel (ASS 316L) and duplex stainless steel (DSS 2205) has been examined and reported. The weld joint was fabricated through the use of gas tungsten arc welding process with a nickel enhanced filler metal ER 2209. The microstructural changes observed in the fusion zone such as nucleation of delta ferrite (δ), austenite (γ) reformation, precipitation of intermetallic phases and the formation of coarser ferrite phases in the HAZ have been reported. Also, the mechanical properties of the weldment such as microhardness, impact toughness and tensile properties have been correlated with microstructural changes. Potentiodynamic polarization test results showed a better electrochemical behavior for ASS 316L than with the weldment and the parent metal of DSS 2205. The austenite phase was found to be electrochemically more stable than the ferrite phase in duplex microstructure. On the other hand, achievement of the stress corrosion cracking resistance by the weldment and the parent metal of DSS was found to be excellent, whereas ASS 316L ended with surface fissures.