Effect of lead and applied potential on corrosion of carbon steel in steam generator crevice solutions

摘要

General corrosion behavior and stress corrosion cracking (SCC) susceptibility of carbon steel in simulated steam generator crevices are probed by voltammetry and electrochemical impedance spectroscopy, coupled to ex-situ characterization of the formed oxides and slow strain rate tests. Impedance spectra are interpreted using the Mixed-Conduction Model allowing for the extraction of oxidation and corrosion release rates. The results indicate a beneficial effect of lead on both general corrosion and SCC susceptibility of carbon steel near the corrosion potential. At anodic potentials, the negative effect of Pb on localized corrosion susceptibility is secondary to that of the applied potential.