Kinetic modelling of Cr2O3 growth on a Ni-30Cr alloy in silicate melts

Abstract Corrosion tests of Ni-30Cr alloy were performed in three simplified soda-silicate and borosilicate melts in order to follow the evolution of the protective chromia layer. A complete identification of the corrosion mechanisms enables the establishment of a kinetic model based on the oxide formation and dissolution rates. The dissolution kinetics is strongly dependent on the chromium solubility limit and diffusivity, which are related to the basicity and viscosity of the melts. This new modelling of the oxide growth is in good agreement with the experimental results.