Numerical Model For Short-Time High-Temperature Isothermal Oxidation of Fe-Mn Binaries at High Oxygen Partial Pressure

Since the oxidation reactions in the process of steel production occur in harsh conditions (i.e., high temperatures and gas atmospheres), it is practically impossible to observe in situ the compositional changes in the steel and the formed oxide scale. Hence, a coupled thermodynamic-kinetic numerical model is developed that predicts the formation of oxide phases and the composition profile of the steel alloy's constituents in a short time due to external oxidation. The model is applied to high-temperature oxidation of Fe-Mn alloys under different conditions. Oxidizing experiments executed with a thermogravimetric analyzer (TGA) on Fe-Mn alloys with different Mn contents (below 10 wt %) are used to determine kinetic parameters that serve as an input for the model. The mass gain data as a function of time show both linear and parabolic regimes. The results of the numerical simulations are presented. The effect of different parameters, such as temperature, Mn content of the alloy, oxygen partial pressure, and oxidizing gas flow rate on the alloy composition and oxide phases formed, is determined. It is shown that increasing the temperature and decreasing the oxygen partial pressure both lead to a thicker depleted area.

Automated summary

Due to the harsh conditions in steel production, it is difficult to observe the compositional changes in the steel and oxide scale in real-time. A numerical model is developed to predict the formation of oxide phases and composition profile of steel alloy during external oxidation. The model is applied to high-temperature oxidation of Fe-Mn alloys and experimental data is used to determine the kinetic parameters. The simulations show that temperature and oxygen partial pressure affect the thickness of the depleted area.