Exploration of the effect of chloride ion concentration and temperature on pitting corrosion of carbon steel in saturated Ca(OH)2 solution

Passivity breakdown on carbon steel, has been studied and the data are interpreted in terms of the point defect model. An increase in temperature from 25 degrees C to 85 degrees C results in a decrease in localized corrosion resistance according to a linear relationship between the critical breakdown voltage, E-b, and log (chloride activity) for all chloride concentrations. The linear dependence of the passivity breakdown potential on the square root of potential scan rate (v(1/2)), as predicted by the PDM, yields an estimate of the critical areal concentration of condensed cation vacancies at the metal/film interface that leads to the passivity breakdown. (C) 2015 Elsevier Ltd. All rights reserved.