What is electrochemical corrosion?

Electrochemical corrosion refers to the corrosion that occurs due to the electrochemical interaction between a metal and an electrolyte. During the process of electrochemical corrosion, a current is generated. Electrochemical corrosion is an extremely widespread form of corrosion. Examples include atmospheric corrosion and soil corrosion. It mainly arises from the formation of numerous micro-galvanic cells on the metal surface, which is contaminated with trace impurities (such as carbon and other metal particles) and covered with a thin film of electrolyte solution. If the base metal is more reactive than the impurities, the base metal will be dissolved and corroded. When the surface of a steel pipe is exposed to humid air, water vapor will condense on the surface while absorbing carbon dioxide from the air, forming a micro-galvanic cell phenomenon and causing electrochemical corrosion.