Mahboobeh Zahedifar

Metallic materials are still the most widely used group of materials particularly in both mechanical engineering and the transportation industry. In addition, metals are commonly used in electronics and increasingly also in the construction industry. However the usefulness of metals and alloys is constrained by one common problem known as corrosion. Corrosion is a naturally occurring phenomenon commonly defined as deterioration of metal surfaces caused by the reaction with the surrounding environmental conditions. Corrosion can cause disastrous damage to metal and alloy structures causing economic consequences in terms of repair, replacement, product losses, safety and environmental pollution. Due tothese harmful effects, corrosion is an undesirable phenomenon that ought to be prevented [1-3].