Corrosion refers to a process that involves deterioration or degradation of metal. The most common example of corrosion is the formation of rust on steel. Most corrosion phenomena are of electrochemical nature and consist of at least two reactions on the surface of the corroding metal. One of the reactions is the oxidation (e.g., dissolution of iron) also referred to as the anodic partial reaction.other is a reduction reaction (e.g., reduction of oxygen), and is referred to as the cathodic partial reaction. The products of the electrochemical reactions can react with each other non-electrochemically to form the final product (e.g., rust). For example, the corrosion of iron to form rust proceeds according to the overall reaction: