Localized Corrosion

Pitting and crevice corrosion are major forms of localized corrosion. Ni-base alloys are widely used because of their resistance to localized environments, which are often oxidizing environments containing chloride. The effects of alloying elements, aggressive ions, inhibitive ions, and oxidizing species are discussed in terms of an electrolyte model. The corrosion behavior of high entropy and multi-principal element alloys is also presented. The role of grain boundary precipitation and inclusions on localized corrosion is reviewed. Intergranular corrosion is another form of localized corrosion, engendered by the precipitation of carbides, nitrides, or intermetallic phases. The effect of alloying elements and thermomechanical treatment on sensitization is discussed for several alloy families. Brief mention is made of dealloying.