What is a Cathodic Protection System?
Cathodic protection is a commonly used method of preventing and controlling corrosion in metal that is especially susceptible to rust and corrosion. Metallic objects that are likely to contain, be near or be submerged in water for a long period of time, such as metal hulled boats or water pipes are often fitted with cathodic protection to prevent their corrosion over time.
How Cathodic Protection Works
Cathodic protection employs a piece of easily corrodible metal, such as zinc or iron, connected to the surface it is intended to protect. Called a “sacrificial anode” or just “anode,” this metal rusts and corrodes in place of the primary piece of metal.
Cathodic Protection Systems & Their Use in the Industrial Industry
Primarily, cathodic protection involves galvanizing a metal. Metals such as steel are coated with a more easily corroded metal, like zinc. As corrosion takes place, the zinc is sacrificed to rust and corrosion while the underlying steel is left largely untouched. A natural electrical current forms between the two levels, helping to attract oxidation and corrosion to the sacrificial zinc.
In objects where a solid electrical current cannot be formed between the metal, another method of cathodic protection adds an external, DC electrical current to draw corrosion away from the protected surface.
Other Benefits & Uses of Cathodic Protection
It has been shown in many cases that applying cathodic protection to an object has a strengthening effect. The obvious explanation is that adding another layer of metal, even a weaker metal, increases tinsel strength and helps to reduce the appearance of stress fractures, cracks, and ruptures.