| Stress corrosion cracking (SCC) susceptibility of the phosphorus de-oxidized copper has been evaluated in synthetic seawater polluted by sulfides using slow strain rate test (SSRT). The effect of concentration of sulfide, temperature, and applied cathodic and anodic potentials on the final strain values and maximum stress were also studied. No cracks were found under the tested conditions. The final strain and maximum stress values decreased but not significantly, with increase in the temperature, applied anodic potential and sulfide concentration. The observed effect is due to the section reduction by uniform corrosion. Lateral cross section and microscopic examination of the fractured specimen ruled out the existence of the localized corrosion. Electrochemical measurements showed that the Cu2S film is not a protective film and also exhibits a mass transfer limitation to the inward diffusion of the sulfides. Based on these results the reasons for the absence of cracking are also discussed. |
