Alloy 22 (N06022) is the current candidate alloy to fabricate the external wall of the high level nuclear waste containers for the designated Yucca Mountain repository. It was of interest to study and compare the localized corrosion susceptibility of several commercial nickel-chromium-molybdenum alloys in 1 M NaCl, 1 M NaF and 0.5 M NaCl + 0.5 M NaF solutions at different temperatures. Standard electrochemical tests such as polarization resistance and cyclic potentiodynamic polarization were used. Studied variables included the type of halide solution, temperature and alloying elements. In general, results show that Ni-Cr-Mo alloys are highly resistant to general and localized corrosion in both chloride and fluoride solutions; however, chloride solutions seemed more aggressive than fluoride solutions.
Key words: nickel alloys, alloying elements, chloride, fluoride, pitting corrosion, crevice corrosion, temperature, polarization resistance, cyclic polarization