An internal oxidation zone with (Mn1 − x,Fex)O mixed oxide precipitates occurs after annealing a Fe – 1.7 at.% Mn steel at 950 °C in N2 plus 5 vol% H2 gas mixture with dew point of 10 °C. Local thermodynamic equilibrium in the internal oxidation zone is established during annealing of the Mn alloyed steel. As a result, the composition of (Mn1 − x,Fex)O precipitates depends on the local oxygen activity. The oxygen activity decreases as a function of depth below steel surface, and consequently the concentration of Fe decreases in the (Mn1 − x,Fex)O precipitates.
- (Mn,Fe)O mixed oxide
- Composition depth profile
- Internal oxidation
- Local thermodynamic equilibrium
- Mn alloyed steel