Corrosion /kəˈroʊʒən/ (Latin corrode – gnawing) – corrosion of metals as a result of chemical or electrochemical interaction with the external (aggressive) environment. Corrosion is classified as follows: according to the geometric nature of the corrosion decomposition (for example, bulk, subsurface, intercrystalline, here and there); according to the nature of the interaction of the metal with the environment – chemical in non-conducting media (gases, oil, etc.) and electrochemical in aqueous solutions of electrolytes; by type of corrosive environment (for example, in the atmosphere, in gas); by the nature of the additional impact that occurs simultaneously with the influence of the aggressive environment of the metal (for example, C. during tension, C. during friction, contact C., C. fret) as a result, objects lose their properties up to the complete destruction of the material. To prevent corrosion, anti-corrosion components are added to the metal (this is how stainless, corrosion-resistant special steels are obtained), protective coatings based on other metals are applied to the metal surface (chrome plating, nickel plating, etc.), objects are painted, etc.