Superior Corrosion Resistance of Ti-Al-Zr Alloy in Aggressive Nitric Acid Environments

This paper describes the corrosion behavior of a Ti-based alloy, Ti-Al-Zr for aggressive nitric acid applications. Corrosion behavior of the materials was established using electrochemical polarization technique, for three process variables encountered in reprocessing plants: (a) nitric acid (1, 3 and 6 M), (b) temperature (25 and 75 °C) and (c) oxidizing ions (Ce⁺⁴ and V⁺⁵ ions). Electrochemical polarization tests established that the Ti-Al-Zr alloy was in passive condition up to a potential of 4000 mV_Ag/AgCl even at 75 °C, and it showed uniform corrosion. SS304L, however, showed severe intergranular corrosion at a much lower anodic potential, thus establishing better corrosion resistance for Ti-Al-Zr alloy in the aggressive nitric acid environment.