The Susceptibility of Copper to Pitting Corrosion in Borate-Buffered Aqueous Solutions Containing Chloride and Sulfide

The formation of sulfide and oxide films on copper (Cu) was studied in chloride solutions with and without added borate and sulfide. Electrochemical experiments demonstrated that Cu sulfide (Cu2S) films formed at considerably lower potentials than oxides (Cu2O/CuO) films. The growth of Cu2S was controlled by a combination of sulfide transport to the reacting Cu surface and the competition between SH− and Cl− ions for adsorption sites on the Cu...