35 / 2015-05-05 15:44:09

Kinetics of the Reaction between Mn in Fe-Mn-C Melt and CO-CO2 Gas Mixture

kinetics，,Fe-Mn-C melt,redox reaction, mixed gas,CO- CO2

High manganese TWIP steel for vehicles has become a hot research field for automotive steel of the next generation due to its good combination of high strength and high toughness. The reaction of carbon in the molten metal reducing MnO in the molten slag is very important during the low-cost smelting/refining of high manganese TWIP steel and depends on the thermodynamics of this reaction. While applying the method of chemical equilibrium between the Fe-Mn-C melt and the mixed gas of CO and CO2 to investigate the thermodynamic property of components, it is necessary to find out the chemical equilibrium time needed, which depends on the kinetics of related reactions in the system. The present investigation uses a Sampling Method and gets the Mn concentration changes in Fe-Mn-C melt with the time to investigate the kinetics of the reaction between the Fe-Mn melt and the mixed gas of CO and CO2. According to the relationship between the concentration and time in different reaction order, the manganese concentration and time were made linear regression. The reaction order whose correlation coefficient of linear regression is closest to 1 is taken as the reaction order of this reaction. After that, the other kinetic data, such as reaction rate constant and apparent activation energy, were obtained. The results show that the reaction between the Fe-Mn-C melt and the mixed gas of CO and CO2, [Mn]+CO2(g)=MnO(s)+ CO(g) , is a 1.5th order reaction. The reaction rate constant is (1.24~1.86)×10-2 wt%-0.5•min-1 and the apparent activation energy of reaction is 74.31 kJ﹒mol-1 based on this reaction order.