The beneficial galvanic effect of the constituent phases in 2205 duplex stainless steel on the passive films formed in a 3.5% NaCl solution

Abstract The galvanic effect of the composed phases in 2205 duplex stainless steel on the passive films formation of the two phases in a 3.5% NaCl solution was investigated by electrochemical measurements and composition analyses. The results show that the galvanic effect benefits the stability of the passive films of both phases. However, the inner part of the α-phase passive layer benefits the most because of the increase in the concentrations of Cr, Ni and Mo in the passive film, the decrease in the formation rate and transfer velocity of the oxygen vacancies, and the reduction in the defect density.