Corrosion of Copper-Nickel Alloys in Sea Water Polluted with Sulfide and Sulfide Oxidation Products

Abstract

The corrosion rates of copper alloys 706 (90:10 Cu:Ni) and 715 (70:30 Cu:Ni) were measured, using rotating cylinder specimens in sea water that contained oxygen, sulfide, sulfur, and polysulfide, either singly or in combination. In addition a control test was performed using unpolluted deaerated sea water. Corrosion rates were monitored for over 24 hours, using linear polarization and potential step techniques. The work has shown that copper-nickel alloys can corrode quite rapidly in deaerated sea water if these normally "passive" alloys are made active by the presence of sulfide, or if sulfur is available as an oxidant.