Current and Potential Relations for The Cathodic Protection of Steel in Salt Water★

Abstract

Abstract A laboratory investigation was made pertaining to the cathodic protection of steel specimens that were exposed for 60 days to both stagnant and aerated city water, to which was added 3 percent by weight of sodium chloride. Major consideration was given to the significance of potential as a criterion for protection. Optimum protection was achieved when specimens were controlled at —0.77 volt with reference to the saturated calomel half cell. Although a good degree of protection was obtained at controlled potentials more noble than —0.77 volt, that is, at the potentials associated with the breaks in cathodic polarization curves, this lesser degree of protection could not be obtained at lower mean current densities. 5.2.4