Corrosion of beta-sialon-based ceramics by molten steel

摘要

The corrosion resistance of sialons made from commercial powders (AlN, Al_2O_3 and Si_3N_4) and from powder precursor produced by carbothermal reduction and nitridation of raw aluminosilicate (pyrophyllite) in molten steel were investigated. The corroded zone in sialon made from raw pyrophyllite (P1) is more then two times deeper compared to the corroded zone of sialon made from commercial powders (Cl). The corrosion zone of sample P1 is on the average 610 mu m deep, while in sample Cl it is only 260 mu m. The main corrosion products are gamma-Al_2O_3 and iron silicides. The phase compositions were estimated by neutron Rietveld refinement.