Effect of chloride on Cu corrosion in anaerobic sulphide solutions

Abstract

The effect of chloride on copper corrosion in anaerobic aqueous sulphide solutions has been investigated using corrosion potential measurements, electrochemical impedance spectroscopy, scanning electron microscopy, focused ion beam and inductively coupled plasma atomic emission spectroscopy. Long-term exposure experiments were performed in 10−3mol L−1 Na2S solutions containing chloride concentrations in a range from 0.1 to 5 mol L−1. Chloride was found to (i) inhibit Cu2S film growth by displacing adsorbed sulphide from the Cu surface; (ii) induce film porosity; (iii) facilitate transport of Cu+ to the solution (at very high chloride concentrations). This paper is part of a supplement on the 6th International Workshop on Long-Term Prediction of Corrosion Damage in Nuclear Waste Systems.