Types Of Steel Corrosion

Corrosion is the process of eroding of the top layer of metals as a result of an electrochemical reaction with the environment. When metals are exposed to moisture or wetness, an orangish discolouration known as rust forms on the surface of the metal. This causes deterioration and the gradual destruction of the metal, if not treated effectively. The study of prevention of corrosion and its treatment is known as Corrosion Engineering.

There are many forms of corrosion. The most common types are explained below.

General Attack Corrosion

This the most common type of corrosion which is also treatable. Also known as uniform attack corrosion, this phenomenon occurs when the entire surface of a metal is exposed to air or a wet surface which results in complete damage of the metal. General attack corrosion generally results in the most amount of destruction to the material however, it can be treated. Hence, it is also known to be the safest form of corrosion.

Galvanic Corrosion

Galvanic corrosion is a phenomenon that occurs when two distinct metals come in contact with each other through an electrolyte. One metal acts as a cathode while the other metal behaves like an anode. The rate of corrosion of the anode metal is amplified while the cathode metal takes longer to deteriorate. Galvanic corrosion can occur only when both the metals are placed in an electrolyte that is susceptible to corrosive action when electricity is passed through it.

Corrosion Engineering

Corrosion is the destructive attack of a material by reaction with its environment. The serious consequences of the corrosion process have become a problem of worldwide significance. In addition to our every day encounters with this form of degradation, corrosion causes plant shutdowns, waste of valuable resources, loss or contamination of product, reduction in efficiency, costly maintenance, and expensive over-design; it also jeopardizes safety and inhibits technological progress.

The multidisciplinary aspect of corrosion problems combined with the distributed responsibilities associated with such problems only increase the complexity of the subject. Corrosion control is achieved by recognizing and understanding corrosion mechanisms, by using corrosion-resistant materials and designs, and by using protective systems, devices, and treatments. Major  orporations, industries, and government agencies have established groups and committees to look after corrosion-related issues, but in many cases the responsibilities are spread between the manufacturers or producers of systems and their users. Such a situation can easily breed negligence and be quite costly in terms of dollars and human lives.