What is corrosion?

Corrosion is usually defined as the deterioration of a metal or its properties caused by a reaction with its environment.
Most metals occur naturally in the form of oxides
usually chemically stable. When exposed to oxygen and other oxidizing agents, the refined metal will try to revert to its natural oxide state. In the case of iron, the oxides will be in the form of ferrous or ferric oxide, commonly known as rust.