Localized corrosion continues to be one of the most difficult forms of corrosion to predict and monitor, making implementing mitigation strategies limited. This reality leads corrosion engineers to use the blunt instrument of alloy selection as the only means of (hopefully) ensuring that such an attack does not occur on an engineering asset. In the late 1960s and early 1970s, the advent of electrochemical techniques in corrosion science was heralded as a way to address the problem by determining the critical conditions needed for pits to nucleate and grow and also those required for pit growth to stop (i.e., the pits to repassivate).
The conceptual framework first suggested by Pourbaix, et al.,1 that a wetted surface needed to exceed some potential (usually referred to as the pitting potential, Epit) for pits to nucleate, and those pits would grow until the potential was below a lower potential...
