| Basing on RH-MFB refining technology investigation in Bao Steel, the paper's centralcontent is decarburization in RH process. The decarburization model is built. Thedisciplinarian of decarburization in RH process and the fluence of technical and equipmentfactors to decarburization rate and effect are analysed in order to supply a credibleacademic gist for setting down rational RH treatment technology and optimization.The existing technical conditions of producing IF steel in Bao Steel are statisticed andanalysed. Now the initial carbon concentration for RH process is mostly between250×10-4% and 350×10-4% ,its ratio in the statistical samples is about 75%(40 samples).The target carbon concentration is (20～30)×10-4% mostly and the ratio is about 82.5%.The average decarburization time is 20 minutes and the average treatment time is 29minutes.On the assumption that the decarburization reaction happens only in the vacuumtank,CO gas generation and its growth to vacuum in the molten steel,forceddecarburization by bubble surface of purging Ar gas and splashing droplets are confirmedthe decarburization mechanisms. According to the kinetics of decarburization reactionand the theory of mass conservation,the mathematical model of RH decarburizationprocess has been established. This model includes natural decarburization and forceddecarburization in order to exert the coercive action of oxygen gun equipped on RHtreatment equipment in Bao Steel. It can simulate decarburization precess and predicteventual carbon concentration preferably. Programming the mathematical model withRunge-Kutta arithmetic that can calculate by computers.Calculated results by model accord with measured values greatly. The accuracy ofterminal carbon concentration is high.Using this mathematical model,the effect of several technical factors and equipmentparameters on decarcurization process. The analysis indicates that eventual carbonconcentration for decarburization process will reduce with increasing of initial carbonconcentration or decrease of initial oxygen concentration in molten steel,the rate ofdecarburization will be bigger with increase of pressure decreasing rate ,shortening timeof flowing low flux Ar gas,increasing Ar gas flux and enlarging diamerter of infusingtubes. In the total decarburization process,the decarburization quantity of molten steel in thevacuum tank is about 49.93% of the total and the percent of splashing droplets is about37.04%. The decarbutrization of splashing droplets is important at the end ofdecarburization process.
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