Temperature has significant influence on the localized corrosion of stainless steels (SSs) and nickel-base alloys. Below a certain temperature, the pitting potential increases steeply,1 and this explains the success of the critical pitting temperature test,2 which has become a standard procedure in alloy development. A similar, much lower, critical temperature exists for crevice corrosion in a standard geometry.
The temperature dependence of pitting corrosion is not well understood, especially around the critical temperature. One limiting situation can be defined, in which the alloy passivates even in the most aggressive (saturated or supersaturated) metal chloride solution that can be developed in the pit. The present authors have determined the temperatures at which this occurs, with the aim of understanding the critical pitting temperature and developing an objective test for alloy development in the NiCrMoFe system.
Various wrought nickel-base alloys and one duplex SS were supplied by the Cabot Corp....
