What is the purpose of impressed current cathodic protection in corrosion control?

The purpose of impressed current cathodic protection (ICCP) in corrosion control is to enhance cathodic polarization. In the context of corrosion, cathodic polarization refers to the process of applying a protective electrical current to counteract the electrochemical reactions that lead to corrosion. This method increases the negative potential of the metal surface, effectively reducing the rate of corrosion by making the metal less noble.

In ICCP systems, an external power source is used to supply a direct current to the anodes, which leads to the generation of a protective electric field around the submerged structure. The current helps polarize the metal substrate, shifting its electrochemical potential to more negative values and providing a sufficient driving force to offset the natural corrosion process.

The enhancement of cathodic polarization is crucial in protecting various structures against corrosion, such as pipelines, storage tanks, and marine vessels, particularly in environments where traditional cathodic protection methods may be insufficient. By maintaining a protective potential, the integrity of the structure is prolonged, and the likelihood of failure due to corrosion is significantly reduced.