Cathodic protection (CP) is a technique to control the corrosion of a metal surface by making it work as a cathode of an electrochemical cell. This is achieved by placing in contact with the metal to be protected another more easily corroded metal to act as the anode of the electrochemical cell. Cathodic protection systems are most commonly used to

♦  Protect steel

♦  Water or fuel pipelines

♦  Storage tanks

♦  Steel pier piles

♦  Ships

♦  Offshore oil platforms

♦  Onshore oil well casings

              Cathodic protection can be, in some cases, an effective method of preventing stress corrosion cracking.