An irreversible interfacial reaction of a material (metal, ceramic, polymer) with its enviroment which results in consumption of the material or in dissolution into the material of a component of the enviroment. Often, but not necessarily, corrosion results in effects detrimental to the usage of the material considered. Exclusively physical or mechanical processes such as melting or evaporation, abrasion or mechanical fracture are not included in the term corrosion.
PAC, 1989, 61, 19. 'Electrochemical corrosion nomenclature (Recommendations 1988)' on page 20 (