Corrosion Behavior of Iron-Nickel-Base Alloy 925 in Salt Solution Containing S, H₂S and CO₂

The uniform corrosion and four point bend-beam stress corrosion tests of iron-nickel-base alloy 925 were conducted in the salt solution containing S, H₂S and CO₂ at 150℃. The corrosion morphology and corrosion product composition were analyzed and the corrosion reaction mechanism was investigated. The results show that after uniform corrosion testing for 360 h, obvious localized corrosion on the surface of the iron-nickel-base alloy 925 was observed; the calculated uniform corrosion rate was 0.37 mm·a^-1; the corrosion product was composed of Fe, Ni and S; the addition of S was the main reason of the alloy localized corrosion. After stress corrosion testing for 1 080 h, no stress corrosion cracking was observed on the alloy; the corrosion product had a large number of element O, indicating that much H₂O or OH^- participated in the corrosion reaction.