Impressed Current Cathodic Protection
Impressed current cathodic protection prevents corrosion by applying an external DC current that shifts the potential of the metal being protected to a more positive value.
Physical-Chemical Mechanism of Action
An external DC current is fed into the electrolyte via insoluble anodes. This shifts the electrochemical potential of the metal to be protected so that it stays in the thermodynamically stable range and cannot corrode.
Metallurgical Relevance & Risks in Welding
Impressed current cathodic protection prevents corrosive substances from attacking the metal. If handled incorrectly or if the current is too weak, protection may fail, leading to susceptibility to corrosion.
Workshop Practice & Action Instructions
Make sure the anode and cathode are properly attached. Choose the current so that the metal remains in the stable range. Continuously monitor the corrosion protection and watch for any changes.