It is generally accepted that stable pits start to form at a certain critical potential known as the pitting potential. The pitting potential is defined in this work as the potential at which pits will initiate and propagate. This potential serves as one of the fundamental electrochemical criteria characterizing the susceptibility of metals to pitting corrosion.
The pitting potential for a certain metal in a particular environment should be a characteristic value. However, various workers have obtained different values even for the same metal in the same environment.1,2 These differences can be caused by sample pretreatment, surface conditions, grain size, small variations of the alloy’s chemical composition, etc., but also by crevice corrosion effects. Stainless steels (SS) are especially susceptible to crevice corrosion. In early investigations,3,4 it was shown that crevices should be avoided during anodic polarization measurements. The critical potential for crevice corrosion is generally below that...
