Understanding of oxide stability is important for processing of sintered steels. The stability of an oxide depends on the alloy composition, temperature and environment for oxidation. The type of oxide and its range of stability can be predicted by thermodynamic calculations. The reactive character of oxygen with metal is a natural difficulty for a thermodynamic study of oxides. In this work, an experimental and computational technique has been developed, allowing for an evaluation of oxide stability.
Oxidation results of Fe-Cr-Mn-Si alloys in Ar/H2 atmospheres will be presented, and compared with calculations. Oxidised Fe-6Cr-3Mn-(0-0.1)Si alloys show mainly a spinel oxide with the formula (Fe,Mn)Cr2O4. Silicon is found in separate oxides, rather than combined Cr-Mn-Si oxides. At low partial pressures it appears to be quartz types of oxide SiO2, and at higher partial pressures olivine (Fe,Mn)2SiO4.