Forms of Corrosion

There are eight major forms of corrosion accounting for the vast majority of corrosion problems observed, along with several lesser seen forms occurring in specific environments. Uniform or general corrosion proceeds independent of the material’s microstructure and component design. It is highly dependent upon the environmental conditions and the material’s composition, generally occurring at a slow rate. All the remaining forms of corrosion are localized, dependent upon the environments, the components and systems designs, and/or the microstructure of the materials. These forms typically produce higher corrosion rates than uniform corrosion, and in some cases can be quite rapid. Each of the various forms of corrosion should be evaluated for a material and environment when designing new systems. The following sections cover all the forms of corrosion observed with some materials’ susceptibilities and general protection schemes for the various forms.