CP Design Center


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 and are 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.

Metallic corrosion generally involves the loss of metal at a particular location on an exposed surface. Corrosion occurs in various forms ranging from a generalized attack over the entire surface to a severe concentrated attack. In most cases, it is impossible or economically impractical to completely arrest the corrosion process; however, it is usually possible to control the process to acceptable levels.

The U.S. government funded a detailed study of the annual cost of corrosion in 1975. The total cost of metallic corrosion to the U.S. economy was estimated at 4% of the GNP ($70 billion dollars). Of that, approximately 30% was defined as avoidable. Adjustment based on today's current economy puts total current costs in the $300 billion range with over $100 billion of that avoidable.