Decarburization Model Of Molten Steel In RH-MFB Device Research

With the development of industrial technology,the demand for iron and steel materials,especially for low carbon steel become more and more high quality requirements.Development of refining outside the furnace technology can further purifying molten steel purity,improve product quality,especially in RH vacuum refining technology.RH-MFB in low carbon steel production has some problems,such as decarburization long time,carbon content is not stable after refining.Through the study of the mechanism,the decarburization RH-MFB model is developed and optimized,which plays a guiding role in the actual production.It is of great significance for the continuous production of the enterprise to improve the prediction rate of the carbon content of the endpoint.The main research contents as follows:In the present study,treating a 210 ton RH reactor as the prototype,a 1:5 scale water model has been developed.The gas-liquid flow behavior,and the effect of different operating parameters on the RH refining process were investigated.The results showed that the gas-liquid two phases will maintain the inherent flow mode after the flow field becomes stable in water model.The gas-liquid flow behavior in RH degasser is determined by the gas flow rate,immersion depth and pressure.The circulation flow rate can be increased by the greater gas flow rate,the deeper immersion depth,and the higher liquid level of the vacuum chamber,which also results in the shorter mixing time.Based on the thermodynamic and kinetic analysis of RH-MFB decarburization process,the decarburization mechanism of RH was determined,and the mathematical model of RH decarburization was established.From the research samples randomly selected 10 samples of furnace,the model validation.Comparison results show that the carbon content in the furnace 10 times sample compared with the simulation model established by the value approach.And A1,A2,A3,A4 samples of carbon content and the simulation values are compared under the condition of the continuous time.Concluded that the carbon content in most of the sample and the model of the simulation value is relatively close,it conforms to the law of RH decarburization within a certain error range.Through the analysis on the whole,as the initial carbon content is reduced,end point carbon content is also reduced.There is a critical value of the initial oxygen content.Under the critical value,the carbon content is lower and lower with the increase of initial oxygen content.There are different critical values for different initial carbon content.The circulating flow rate will increase with the increase of the gas flow rate,and increase the internal reaction area of the molten steel,which is beneficial to the decarburization of molten steel.Therefore,in order to improve the continuity of the RH-MFB production and improve the prediction rate of carbon content in the end of the carbon dioxide,the model needs to be optimized.Finally,it is concluded that the model is in accordance with the law of RH decarburization in the error range.At the same time,there is a certain requirement for the initial carbon content and initial oxygen content in the smelting of low carbon steel,and the gas flow rate should be controlled at 2400NL/min,so as to achieve a better smelting effect.