Passivity breakdown, its relation to pitting and stress-corrosion-cracking processes

Repassivation kinetics of metals has been frequently related to the susceptibility to localized types of corrosion such as pitting, crevice corrosion and stress corrosion cracking (SCC). The present paper reviews recent work in our laboratory showing that repassivation kinetic measurements can be successfully used to detect passivity breakdown in metals; a step which followed by localized acidification leads to pitting and crevice corrosion. Similar experiments have confirmed that for SCC a slow repassivation rate is a necessary, but not a sufficient, condition for stress corrosion cracking.