Introduction to Electrochemical Corrosion

The corrosion that occurs when a metal reacts electrochemically with an electrolyte is called electrochemical corrosion. 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 due to the presence of trace impurities (such as carbon and other metallic particles) and 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 condenses on the surface while simultaneously absorbing carbon dioxide from the air, leading to the formation of a micro-galvanic cell phenomenon and causing electrochemical corrosion.