Cathodic Protection
The prevention of corrosion by forcing the metal to be protected to act as a cathode.
Unit
V
In depth
Protection is achieved either by attaching a more reactive sacrificial metal or by applying a small direct current from an external supply through an inert anode. Either way the protected structure receives electrons and cannot be oxidised.
Examples in the real world
Impressed-current systems protecting buried pipelines; magnesium anodes on ships' hulls and in water heaters.