Search

The current investigation delves into the oxidation resistance of magnesia‐carbon‐bonded (MgO‐C) refractory enhanced with calcium magnesium aluminate (CMA) cement, metallic aluminum, and Carbores P across a broad temperature spectrum from 800 to 1600 °C. The results demonstrate that the modification with CMA up to a temperature threshold of 1200 °C does not compromise the material's inherent oxidation resistance. However, above this temperature, a decrement in oxidation resistance is observed. The impact of grain size variation in CMA on the oxidation resistance of MgO‐C refractories is notable, and the finer grains show a superior performance. MgO‐C sample with Carbores P has excellent oxidation resistance up to 1000 °C, while above 1200 °C, its oxidation resistance strongly deteriorates. The metallic aluminum addition exhibits a remarkable oxidation resistance throughout the evaluated temperature range, indicated by a slight oxidation. [ABSTRACT FROM AUTHOR]

Pure alumina (Al2O3) and carbon‐bonded alumina (Al2O3−C) are used to investigate their interaction with iron (Armco) at 1625 °C, applying the sessile drop method. The investigations are conducted inside a heating microscope for 1 h under argon atmosphere with low oxygen partial pressure. No whiskers formation is observed from the experiments with pure Al2O3 and molten iron. In the case of Al2O3−C/Fe system, several phenomena including the decarburization of Al2O3−C, Al2O3−C dissolution in molten iron, Al2O3 layer formation on the iron droplet, and Al2O3 whiskers formation are observed. To clarify the possible influence of iron on Al2O3 whiskers formation, blank Al2O3−C samples without the presence of iron are heated and held in a half‐sealed platinum crucible at 1550 °C for 2 h. Thereby, the Al2O3 whiskers formation is detected. Finally, the experimental investigations are supported with thermodynamic simulations. [ABSTRACT FROM AUTHOR]