Effect of Mo on interaction between α/γ phases of duplex stainless steel

The role of molybdenum in the interaction of the composed phases of 2205 duplex stainless steel (DSS) in the 3.5-wt% NaCl solution was investigated, by comparing the untreated 2205 DSS sample with two single-austenite and single-ferrite samples prepared via selective dissolution. The results demonstrate that, the interaction is beneficial to the whole passive film properties of 2205 DSS by promoting both the γ-phase and α-phase. The passivity of 2205 DSS at high potential strongly depends on the protective ability of Mo species. Compared with α-phase and γ-phase, Mo species of the 2205 DSS are more capable of keeping stable and being beneficial to passive film recovery, which make 2205 DSS show enhanced performance in pitting resistance and repassivation.