Microstructure Changes of Aluminum Titanate Refractory Doped SiO2 and ZrO2 in Molten Steel

摘要

Aluminum titanate (AT) ceramics has high potential as alloy casting refractory materials due to their good thermal shock resistance which results from their low coefficient of thermal expansion. In a previous study, AT doped SiO2 and ZrO2 were developed to achieve stability and mechanical strength at high temperature. In this work, the changes of microstructure of AT doped SiO2 and ZrO2 were investigated in molten steel. A finger rotating test of sintered AT was carried out at 1300 degrees C for 30 min, 1 h, 2 h, and 3 h. Even if there was no reaction between AT and molten steel, a new surface was formed, followed by the decomposition of AT by the heat from molten steel, which was dominantly constituted of Al and Si due to decomposition of AT and Mullite phases. Some of the new surface layer was found to have been eroded by fluctuations of the molten steel.