Dynamic Interaction Of Alumina-Magnesia Castables And Different Alloy Steels

As we all know that the steel has been a significant basic industry of national economy.So we need to improve the quality of steel,so as to advance the research and production of clean steel such as marine engineering,rail transit,aerospace.Refractory is contact with molten steel among the smelting directly,which affects the cleanliness of molten steel.Therefore,in view of the complexity of steel refining conditions,it is of great theoretical value and practical significance to study the interaction between refractory and molten steel of different alloys under dynamic conditions.In this paper,the interaction between alumina-magenesia castable and different alloy steels in dynamic conditions was simulated by the vacuum induction furnace,the corrosion mechanism of molten steel on alumina-magenesia castable and its effect on cleanliness of molten steel were discussed,the interface behavior between different alloy molten steel and alumina-magenesia castable was compared and analyzed.The main conclusions are as follows:?1?Dynamic corrosion mechanism of molten steel to refractory:A low melting point liquid layer was formed with molten steel penetrating and reacting to refractory,which would be emulsified and coiled with moving molten steel.And then the molten steel was reacted with the new interface of refractory,which made the corrosion of refractory continuous.An empirical formula for the size of emulsion droplets was established by dimension analysis.The modified capillary number?Ca*?could be used to determine the critical conditions of emulsification between the reaction layer and molten steel.?2?The composition of reaction layer between refractory and different alloy steel was quite different.High melting point and high viscosity interface layer could effectively inhibit the further penetration and erosion of molten steel to Al₂O₃-MgO castable.Thereinto,the isolation layer was not formed with the reacting between Al₂O₃-MgO castable and common alloy steel,the?Fe,Mg,Mn?Al₂O₄ composite spinel isolation layer was formed with reacting between Al₂O₃-MgO castable and high manganese steel,and Mg-sialon solid solution isolation layer was formed between Al₂O₃-MgO castable and high nitrogen steel.SiO₂ was produced by reacting with high silicon steel,which can increase the viscosity of interface layer and reduce the emulsification of molten steel.?3?The change of alloy elements and inclusions content in steel was consistent with the corrosion of refractory with smelting time prolongation.The change of alloying element content in common alloy steel was not obvious.The initial reaction between[N]and Al₂O₃-MgO castable was the most intense,and the consumption of[N]was more than 50%,which also made a large increase of[O]in steel;SiO₂ was formed due to the combination of Si and decomposed[O],which Si was decreased by¹0%.The content of Mn was consumed²0%because the reaction between Mn and Al₂O₃-MgO castable.The percentage of inclusions in the steel was increased,the increase was about 1.04�,9.29�,0.42�and 0.11�,respectively,in general alloy steel,high nitrogen steel,high manganese steel and high silicon steel.