Re-passivation rate and conduction mechanism of surface film on copper in nitrite solutions

In this work, an effort was put to verify the usefulness of the potential step re-passivation technique in studying the stress corrosion cracking (SCC) susceptibility of copper in environments simulating the final repository of high-level nuclear waste. Validation experiments in NaNO2 solutions (0.005, 0.05 and 1.0 M) showed that the technique is applicable with certain boundary conditions. In addition, conduction mechanism of passive films on Cu in nitrites is studied with impedance spectroscopy and quantitatively modeled by the Mixed-Conduction Model for oxide films. As a result, possible correlations between electrochemically derived parameters and SCC susceptibility are found and discussed.