Thermodynamic Properties Of Main Component Of Mn And C In TWIP Steel Smelting

In contemporary automotive industry booming,car safety and lightweight energy saving is more attention.TWIP steel is to increase the use of the car body strength and an effective way to reduce vehicle weight.But the metal Mn lively,there is a big problem in the smelting of alloying process.C oxide to inhibit the oxidation of Mn,is a low-cost high-manganese steel smelting important way.The fundamental security depends on the thermodynamic go carbon manganese.This first need liquid iron and manganese and carbon-related activity,requiring activity interaction coefficient data on the components.Because manganese content in steel up to 18～33%,it must be considered second-order interaction coefficient data manganese.Refer to the literature study,based on the determination of C and Mn activity and activity coefficients using chemical equilibrium method and obtain the coefficient data for carbon manganese activity first and second order interactions.Through this study can be used to determine the vehicle key process parameters of high manganese steel smelting smelting process and various process steps of the theoretical basis for determining vehicle to provide theoretical guidance AOD refining refining practice with high manganese steel.The thermodynamic data of the existing experimental data can TWIP steel smelting process required to play a complementary role,has a more important theoretical value and practical value.In this study,thermodynamic analysis of the liquid metal component activity research questions,first determined the Fe-Mn-C melt and CO-CO2 equilibrium reaction time and study the Fe-Mn and Fe-Mn-C melt kinetic body with CO and CO2 mixed gas reaction process.After the Fe-C and Fe-Mn metal melt chemistry with CO and CO2 gas mixture to balance the research activity coefficient of carbon in the molten metal and manganese and the first-order and second-order interaction coefficient itself;Using Fe-Mn-C molten metal with CO and CO2 gas mixture of chemical equilibrium study of the activity coefficient of the liquid metal carbon and manganese,and carbon-manganese and manganese on the carbon activity of first and second order interaction coefficients.The results show that:(1)Mn oxide in liquid iron and CO2 reduction reaction equilibrium time of 12.95h.Fe-C melt C elements and CO2 reaction equilibrium time is 8.17h.(2)Mn oxide in liquid iron and CO2 reduction reaction reaction order shall be 1.5,it is a more complex,multi-step reaction.And get their reaction rate constants,the apparent activation energy is 74.314k J.mol-1.(3)By 1600℃,within Fe-C system eCC=-56.524,rCC=-1810.7,within Fe-Mn system eMnMn=-24.355,rMnMn=193.83.(4)In the Fe-Mn-C system,eMnC=109.46.eCMn=23.882,rCMn=252.62.