Electrochemical theory of Corrosion

Electrochemical corrosion or wet corrosion takes place on the metal when it’s exposed to environment in the presence of moisture. According to this theory, 

• Corrosion of metals occurs due to the formation of galvanic cells with anodic region and cathodic region all over the metal substance.

• Anodic region s undergoes oxidation forming metal ions and liberating electrons and suffers from corrosion.

• At cathode region, reduction take place using electrons liberated at the anode.

• Corrosion continuous as long as both anodic and cathodic reactions takes place simultaneously.