Galvanic Cathodic Protection (Galvanic CP)
Definition - What does Galvanic Cathodic Protection (Galvanic CP) mean?
Galvanic cathodic protection is an corrosion prevention method. Galvanic cathodic protection utilizes electrochemical means to protect a base material from corrosion. It does this through the use of a sacrificial anode that corrodes before the material that is being protected. Galvanic cathodic protection is one of the most commonly employed forms of cathodic protection because of its ease of use.
Corrosionpedia explains Galvanic Cathodic Protection (Galvanic CP)
Galvanic cathodic protection requires a sacrificial anode in order to protect the desired material. The anode must be more electrochemically reactive than the material that is being protected. Since the anode is more electrochemically reactive, it will corrode before the protected material, so long as they are in electrical contact with one another. Sacrificial anodes can come in many different shapes and sizes. An example of a sacrificial anode would be a block of zinc that is attached to a steel plate.
Galvanic cathodic protection relies on the potential difference between the sacrificial anode and the cathode, or the material being protected from corrosion. The larger the potential is, then the more protection there will be. Galvanic corrosion protection is so simple because it does not rely on exterior electrical sources. However, when the potential difference from the two materials alone is not sufficient to protect the cathode, then the potential must be increased through the use of specialized equipment. This is a different type of cathodic protection called impressed current cathodic protection.
Cathodic protection is frequently used for:
- Maritime vessels
- Oil platforms
- Storage tanks
- Underground applications