Effect of Heating Atmosphere on Properties of Al2O3-SiO2 Castables Containing Si Powder

摘要

In order to enhance the hot strength of pre-cast shapes of high alumina castables used in industrial furnaces,the present work explored the approach to using in-situ formed bonding phases by incorporating 3％-9％ silicon powders in bauxite based ULC castables.The pre-cast specimens were dried and then heated at 1450°C in air,CO (carbon embedded) and N2 atmospheres respectively.The in-situ formed oxide or non-oxide phases derived from Si can remarkably improve HMOR of the castables,especially after the nitridation treatment.Best thermal shock resistance can be obtained by Si incorporation and heating in reducing atmosphere.The microstructure of the related castable samples was interpreted.