| Continuous casting mold slag plays the role of heat insulation and heat preservation,prevention of molten steel oxidation,absorption inclusion,lubrication and heat transfer in the traditional continuous casting production process.In particular,the lubrication function is particularly important for the quality of the slab and continuous casting.Soft contact electromagnetic continuous casting is a new steel slab continuous casting technology.The technology proposes to make the production of defect-free slabs possible,which can meet the requirements of slab continuous casting and rolling on the quality of slab.However,after applying this technology,the molten steel meniscus in the continuous casting mold will be deformed,and the protective slag channel will be widened,so that the flow of the protective slag slag will be smooth,which will inevitably improve the lubrication condition of the slab and reduce the surface vibration marks and cracks.Therefore,research on the lubrication behavior of the mold flux between the crystallizer and the slab under the action of electromagnetic field,further improve the theory of soft contact electromagnetic continuous casting,and promote the industrialization process of soft contact electromagnetic continuous casting technology.By studying the influence of electromagnetic field on the physical and chemical properties of continuous casting slag,it was found that the viscosity of the slag increased and the average heat flux increased after the application of the magnetic field.The type of precipitation of the mold flux crystals did not change,but the amount of crystal precipitation or growth changed.The molecular dynamics software was used to analyze the change of slag structure of CaO-SiO2-Al2O3-MgO slag system with and without magnetic field and different magnetic field strength.The influence of electromagnetic field on the microstructure of the protective slag was studied.It was found that the action of the magnetic field affected the structure of the slag,but did not have much influence on the stacking of molecules and atoms in the slag.The larger the magnetic field strength,the more the ion clusters in the disordered state increase,and the slag viscosity decreases.Starting from Maxwell's equation,the electromagnetic field distribution of soft contact crystallizer and the mathematical model of Joule heat were established.The attenuation law of electromagnetic field in the crystallizer and the electromagnetic force,electromagnetic pressure and the amount of Joule heat generated were investigated to study the influence on the lubrication behavior.By studying the heat transfer problem in the soft contact electromagnetic continuous casting mold,the mathematical model of solidification and heat transfer of molten steel in soft contact crystallizer under Joule heating is established.The heat transfer between the molten steel and the shell,the heat transfer between the shell and the mold,the heat transfer between the crystallizer and the cooling water,and the heat carried away by the cooling water were examined.The total heat and average heat flow of the molten steel per unit time with and without Joule heat.The mathematical model of lubrication behavior of continuous casting protection slag under high frequency magnetic field is established.The mathematical model is used to study the protection of slag width,meniscus height,slag dynamic pressure,slag consumption and friction under the action of magnetic field during initial solidification.The effect of slag lubrication behavior.It was found that the action of the magnetic field broadened the width of the slag track,increased the height of the meniscus,and reduced the positive and negative pressures caused by the vibration of the crystallizer.The slag consumption is increased and the total friction between the slab and the mold is reduced.Lowering the initial freezing point and improving the lubrication between the casting blank and the crystallizer is beneficial to the surface quality of the casting blank.According to the study,the optimal value of the magnetic field strength is about 40 mT.Figure60,Table26,Reference105. |
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