Historical Understanding of Acid Chloride Passivity Breakdown on Fe-Cr Alloys and New Insight Derived from Artificial Passivation Film Experiments

摘要

It can be concluded that the attainment of X_(cr) = ca. 0.6 of passive film is very important for the attainment of immunity against the passive film breakdown in 1M HC1. If there is a locally Cr-depleted part, of which Cr content is less than X_(cr) = 0.6, in the passive film with the X_(cr) value higher than 0.6, the part suffers from the reductive dissolution and then pitting occurs by the anodic dissolution of matrix alloy at the part.