Improved Corrosion Resistance of Al2O3-SiC-C Castables Due to In Situ Synthesized TiC/TiN.

In order to improve the corrosion resistance of Al₂O₃-SiC-C castables, super- fine TiO₂ (SFT) powder was added directly to the castable with the aim of synthesizing TiC/TiN through in situ reactions. Thermodynamic calculations carried out by FactSage suggested that it was possible to synthesize TiC/TiN through in situ reactions. Analysis performed by X-ray diffraction (XRD) and a scanning electronic microscope equipped with an energy diffraction spectrum analyzer (SEM-EDS) indicated that TiC/TiN was synthesized in the Al₂O₃-SiC-C castable. The corrosion resistance of Al₂O₃-SiC-C castables with and without 2 mass-% SFT was compared after a static crucible corrosion test with the assistance of SEM-EDS and XRD. It was clear that the corrosion resistance of Al₂O₃-SiC-C castables with added SFT was much better than that without added SFT. This might be associated with the location of the in situ-formed TiC/TiN solid particles in the liquid slag, which would prevent the penetration of molten slag into the structure through their effect on the viscosity increment of liquid slag. [ABSTRACT FROM AUTHOR]