Mechanisms of Corrosion of Copper-Nickel Alloys in Sulfide-Polluted Seawater

摘要

We have investigated the importance and effects of various variables on the corrosion mechanism of two copper/nickel alloys, CA706 (90%Cu-10%Ni) and CA715 (70%Cu-30%Ni) in seawater. The variables investigated were dissolved oxygen content, sulfide content, pH, flow velocity, sulfide preexposure, various sulfide species, and simultaneous exposure to sulfide and oxygen. The presence of sulfide in seawater was found to prevent formation of the protective corrosion product that normally forms on copper/nickel alloys, Therefore, when both sulfide and oxygen were present in the seawater, the corrosion of the alloys was greatly accelerated. A qualitative model was developed to explain the mechanism of uniform corrosion of copper/nickel alloys in various seawater environments. (Author)