Corrosion behaviour of Ti alloy TA8-1, Cu alloy B19 and Cu as candidate materials for nuclear waste containers under early deep geological conditions

The corrosion behaviour of Ti alloy TA8-1, Cu alloy B19 and Cu are studied under simulated early deep geological conditions of Beishan, China. In the short-term experiment, the influence of temperature on the corrosion properties of the studied materials is investigated by electrochemical impedance spectroscopy (EIS), potentiodynamic polarisation and cyclic polarisation. In the long-term immersion tests, the evolution of corrosion behaviour is investigated by EIS, in combination with SEM, XPS and Raman analysis. The results show that Ti alloy TA8-1 has the minimum corrosion current density (10(-7) A cm(-2)) and low pitting susceptibility, attributed to the formation of a thin passive film. Cu has the relatively high corrosion current density (similar to 10(-5) A cm(-2)) and low pitting susceptibility. The corrosion resistance of the Cu2O/Cu-2(OH)(3)Cl deposit layer is maintained during the two-month immersion test at 50 degrees C. Severe localised corrosion occurs on the surface of B19 and the corrosion resistance deteriorates obviously during the immersion test.

Automated summary

The corrosion behavior of Ti alloy TA8-1, Cu alloy B19, and Cu under simulated early deep geological conditions in Beishan, China have been studied. The results show that Ti alloy TA8-1 exhibits the lowest corrosion current density and low pitting susceptibility due to the formation of a thin passive film. Cu has a relatively high corrosion current density and low pitting susceptibility. Severe localized corrosion occurs on the surface of Cu alloy B19, leading to a noticeable deterioration in corrosion resistance during the immersion test.