Corrosion and Cathodic Protection on Underground Storage Tanks

The act of corrosion is a natural process for many materials. The rate at which metals corrode depends on their innate energy levels. When electrically connected, metals with high energy levels are used as anodes to protect metals at lower energy levels. Examples of high-energy level metals are magnesium and zinc. A lower-energy level metal such as steel becomes a cathode when it is coupled with a high-energy level metal. The protective corrosion cell becomes active when both metals are placed in the same electrolyte and are electrically connected via a metallic path. In practical application, a protective corrosion cell is known as a cathodic protection system.