The effects of σ phase on localized corrosion of 2205 duplex stainless steel in the presence of Pseudomonas aeruginosa

Abstract

Pitting and galvanic corrosion of 2205 DSS with σ phase were investigated in the presence of Pseudomonas aeruginosa. Pitting corrosion was accelerated by σ phase, and further promoted by P. aeruginosa. The σ phase changed the distribution of pitting sites from being concentrated on phase boundaries and α phase in the solution treated coupons to being around σ phase in the biotic medium. The galvanic corrosion between α and γ phases was enhanced by the bacterium, and σ phase led to anodic dissolution of γ phase instead of α phase in DSS with solution treatment.