Role of Microstructure on the Corrosion Susceptibility of UNS S32101 Duplex Stainless Steel

Abstract

Effect of heat treatments and resulting changes in microstructure on general and localized corrosion susceptibility of lean duplex stainless steel UNS S32101 in caustic and chloride solutions was investigated. Results show that changes in the microstructure (ferrite phase/austenite phase ratio and inter-metallic precipitation) of the duplex stainless steel (DSS), due to different annealing and aging treatments, affect its general and pitting corrosion resistance. The role of DSS microstructure in localized corrosion susceptibility was found to be significantly different in the chloride environments as compared to caustic environments.