Electrolytic corrosion

Electrolytic corrosion is a process in which metal is degraded by contact with an electrolyte (e.g. water or damp soil) and an electrical voltage. This corrosion occurs when two different metals come into contact with each other in a conductive medium and an electric current flows.

The less noble metal (anode) is oxidized and dissolves, while the more noble metal (cathode) remains protected. The electrolyte serves as a medium that conducts the electric current between the two metals. A typical example of electrolytic corrosion is the destruction of underwater ship parts through contact with seawater. In order to prevent electrolytic corrosion, sacrificial anodes made of a less noble metal are often attached, which take over the degradation through oxidation.