工业纯钛TA2在含硫化物深海水环境中的应力腐蚀行为

The deep seawater environments is highly corrosive due to the characteristics of large hydrostatic pressure, low dissolved oxygen and complex aggressive ions. The corrosion and stress corrosion mechanisms of titanium and titanium alloys in deep sea environment are still unclear, which poses a great threat to the application of titanium alloys in deep sea environments. The electrochemical behavior and stress corrosion behavior of industrial pure titanium TA2 in simulated deep sea environment were studied by electrochemical method and U-bend test. Results show that the hydrostatic pressure promotes the uniform corrosion of TA2 and the cathode hydrogen evolution reaction (HER). With the increase of hydrostatic pressure, the corrosion current density and cathode HER current density of TA2 increase. The addition of sulfides reduces the stability of the TA2 passive film to a certain degree, and promotes the cathode HER. The stress corrosion test shows that TA2 has stress corrosion sensitivity under the effect of sulfide ions in deep sea water. The SCC mechanism is mainly hydrogen-induced cracking for TA2 in deep seawater environment. However, due to the difference in oxygen content between deep sea and shallow sea, anodic dissolution mechanism is also one of the reasons for SCC.