Correlation between chromium physicochemical properties in silicate melts and the corrosion behavior of chromia-forming alloy

The relationship between the corrosion behavior of a Ni-30Cr alloy and the physicochemical properties of chromium in silicate and borosilicate melts at 1150 °C has been investigated. Three glass compositions have been chosen in order to identify the effect of basicity and viscosity. The chromium solubility limits in borosilicate melts have been determined and compared with the basicity of the melts. The chromium diffusion coefficients in the melts have been determined with the square-wave voltammetry method. A strong impact of the melt viscosity has been found on the corrosion behavior of the Ni-30Cr alloy. This dependency indicates a mechanism involving a diffusion-limited process for the dissolution of the oxide.