CATHODIC PROTECTION OF UNDERGROUND REFINERY EQUIPMENT
Peter Sherwood · Anti-Corrosion Methods and Materials · 1957
Corrosion is an electrolytic phenomenon. The corroding metal is at higher potential than its surroundings. Accordingly, there will be a flow of electricity away from the metal, leaving the metal in an ionised (oxidised) state. Chemical combination with oxygen from the surroundings must occur simultaneously for electrical balance.