Properties of Self‐Glazing Al ₂ O ₃ ‐C Refractories Influenced by the Graphite Content and Nanoscaled Additives

Components based on carbon‐bonded alumina refractories are widely used in steelmaking industry in terms of submerged entry nozzles, monoblock stoppers, and ladle shrouds. According to the current state of the art, such components are glazed to inhibit oxidation of carbon‐containing refractories. Carbon oxidation leads to a deterioration of the components properties, risking even a detrimental failure and should therefore be prevented. In this paper, alumina–graphite refractories were produced according to standard commercial practice and mechanical, as well as physical properties were determined with special focus on carbon content and the application of nanoscaled additives. The investigations showed a correlation between porous structure and generation of a self‐glaze after heat treatment in air, effectively inhibiting the oxidation process. Moreover, the mechanical and thermo‐mechanical behavior of the tested samples was comparable to commercial components. These newly developed self‐glazed Al ₂ O ₃ ‐C refractories could have the potential to replace the currently used components in the near future.