14.1. What is metal corrosion?

Metal corrosion refers to the degradation of metals caused by chemical or electrochemical reactions with their surrounding environment. Rust formation represents the most common manifestation of this process. Based on the nature of the corrosion mechanism, it can be categorized into chemical corrosion and electrochemical corrosion. Depending on the medium involved, it is classified as atmospheric corrosion or soil corrosion. Furthermore, according to the extent of damage, it is divided into continuous corrosion and localized corrosion.