Stress Corrosion Cracking Behavior of 90/10 Cu–Ni Alloy in Sodium Sulfide Solutions

The stress corrosion cracking (SCC) of 90/10 Cu–Ni alloy in sulfide solutions is not reported in the literature. The SCC behavior of the alloy was studied in dilute and concentrated Na2S solutions at room temperature. The alloy was found to be susceptible to SCC under slow strain rate conditions in the concentrated (0.1 to 1 M) sulfide solutions, but not in the dilute (0.002 to 0.03 M) solutions. On the basis of electrochemical data and ERMA analysis of the metal/film interface of the cracked samples, the mechanism of cracking can possibly be attributed to a dealloying (selective dissolution) phenomenon where the copper matrix but not the solute Ni is selectively removed.