THE WORK REPORTED in this paper is part of a general program of research designed to evaluate the various factors involved in the use of magnesium anodes for the cathodic protection of steel in sea water. Previous work1 has shown that certain magnesium alloys are satisfactory sacrificial anodes for sea water, service being characterized by high solution potentials, comparative freedom from polarization effects, and by low metal consumption per ampere hour of current realized. It was shown that virtually complete protection can be achieved at current densities of from 3-6 MA/Sq. Ft., depending upon the method of application. This prior work exclusively dealt with a continuously immersed cathode which was subject to relatively uniform corrosion attack.
The present work deals with the application of cathodic protection to steel structures, such as marine piling, where varying conditions of exposure and non-uniform corrosion attack are encountered. The corrosion profile of such...
