| Electromagnetic fields exist widely in the field of metallurgy,and the thermal and force effects of electromagnetic field are important means for smelting new steel grades and improving steel quality.The refractories are essential materials for ensuring the operation of metallurgical industry and technology development.The refractories participate in the whole process of steel melting,and their damage not only affects the safe and efficient operation of the metallurgical furnace,but also has an important impact on the quality of steel.Alumina-magnesia refractory is an important lining material in steel smelting process,the corrosion and penetration are the main damage forms.The metallurgical slag is in the molten state at high temperature,and it is conductive because there are a large number of ions and ion groups that can move freely.The electromagnetic field will affect the interface behavior between refractory material and molten slag due to the force effects of electromagnetic field.Therefore,for the alumina-magnesia castables used in steel refining,the numerical simulation and experimental methods were combined.Firstly,the slag corrosion of alumina-magnesia castables under alternating magnetic field was studied,the influence of iron oxides was discussed,and the slag corrosion mechanism was analyzed.Then,based on the controllability of the static magnetic field,the high temperature properties of the slag and its corrosion behavior to the alumina-magnesia castables were studied.Finally,considering the the corrosion of Marangoni convection happened at refractory-slag-air three-phase interface,modification and construction of the local corrosion model was discussed and the effect of static magnetic field was explored.The results are as follows:(1)Alternating magnetic field can aggravate the corrosion of slag on alumina-magnesia castables,especially,the Fe and Mn elements are influenced by the alternating magnetic field and migrate to the interior of the refractories.At the same time,due to the electrowetting phenomenon caused by alternating magnetic field,the wetting angle between the slag and the alumina-magnesia castables decrease,which accelerating the corrosion and penetration of the slag;and the slag corrosion in the same direction of the magnetic field is obviously more serious than that in the normal direction,which also indicates that corrosion and penetration are affected by the electromagnetic force.(2)The application of a static magnetic field can increase the viscosity of theslag and the wetting angle of the slag and the corundum.The corrosion and penetration of slag on the alumina-magnesia castables were decreased,due to electromagnetic damping.And the higher the magnetic induction intensity is,the lower the penetration depth of slag got.The simulation results are verified by the experimental results,which shows that the established corrosion model can be used to simulate and predict the corrosion behavior of alumina-magnesia castables.(3)The three-phase interface corrosion model was modified and the calculated corrosion depth error is less than 4.8%,and the corrosion velocity error is less than6.8%,which has a high goodness of fit with experimental results.;a large number of bubbles in the slag formed lots of gas-liquid-solid interface,which accelerated the corrosion to refractories,and the bubbles added an additional pressure to the slag,accelerating the penetration and corrosion of slag;for slag corrosion at three-phase interface,transverse magnetic fields reduce the velocity of Marangoni convection and suppress the intrinsic movement of the slag.The longitudinal magnetic field has less influence on the Marangoni convection and slightly increases the maximum slag velocity at the three-phase interface,but it can also suppress the intrinsic movement of the slag. |
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