High temperature corrosion behavior of Ni-based alloys

The high temperature corrosion behavior of N07263, N06600, and N06625 in LiCl-Li₂O molten salt was investigated at temperatures ranging from 650 to 850 °C in a glove box. The high temperature corrosion behavior was observed using measurements of the oxide morphology and thickness, the extent of internal corrosion, and the compositional changes in the scale and in the substrate. Corrosion tests were performed, and these demonstrated that the main corrosion products were Fe(Ni,Co)₃, FeNi₃, and LiCrO₂. The internal corrosion of N07263 was localized, while that of N06600 maintained intergranular corrosion throughout the test temperature range. N06625 exhibited uniform intergranular corrosion behaviors at low and high temperatures. N07263 exhibited superior corrosion resistance, as evidenced by its corrosion layer which was more continuous, dense, and adherent when compared with those of N06600 and N06625.