Morphology of Calcareous Deposits Produced on Cathodically Protected Steel in the Deep Ocean

Corrosion control of stationary offshore structures is accomplished by means of cathodic protection. The electric currents of the cathodic protection system cause the deposition of minerals on the submerged metal, and this mineral coating becomes the primary source of corrosion control. The results of a laboratory study of the effect of hydrostatic pressure on the minerology of deposits formed under cathodic protection conditions on carbon steel are presented. In deep ocean waters, the primary deposits are of magnesium minerals and calcareous deposits, if any, are secondary.