A Study on the localized corrosion and repassivation kinetics of Fe-20Cr-xNi (x=0-20 wt%) stainless steels via electrochemical analysis

Abstract

Effects of Ni on the film breakdown, repassivation and dissolution processes of Fe-20Cr-x Ni (x = 0 similar to 20 wt. %) stainless steels (SSs) were examined in a chloride. Among the SSs, Fe-20Cr-10Ni is the weakest to meta-stable pitting corrosion, due presumably to the highest defect density in its passive film. Scratch electrode tests reveal that the repassivation rate of the SSs increases with an increase or a decrease in nickel content from 10 %. Pit growth rate of the SSs decreases with Ni content. However, Fe-20Cr-10Ni alloy forms a pit with the highest aspect ratio, corresponding to its lowest repassivation potential.