Study Of Recarburization With Bottom Powder Injection Through Ladle By Numerical Simulation And Experiment

In modern external refining, the most important metallurgical reaction is carried out in ladle,including desulfuration,deoxidation,decarbonization,alloying, alloy composition trimming,degassing, removal of non-metallic inclusion, modification treatment and temperature control. Inmodern external refining, ladle bottom blowing technology develops more quickly, it has become anindispensable and important link of steelmaking process. Because of the slag removal process in thetraditional recarburization process,there are some problems, large labor intensity, more heat loss,long operation time, the uneven of carbon element distribution, the lack of representativeness ofsampling analysis. Top spray carburization process has good thermodynamic and kinetic conditions,its carbonization effect is better than the traditional process. But the top spraying process has someproblem too. It has the phenomenon of serious spray,metal loss, liquid steel pollution of airbrush,long processing time, high temperature drop, high investment, reoxidation and nitrogen uptake.Combine of dusting technology and ladle bottom blowing technology, this paper presents theladle bottom spray carburization process.First, this paper studies by means of numerical simulation. The90t ladle of Bao tou Iron andSteel Corporation is the object this study. Use the FLUENT to establish a suitable mathematicalmodel and boundary conditions. Use the reasonable hypothesis and simplification to do thenumerical simulation. Then study the form of the flow field of different slot plug location and argonflux, then compare and analysis the field effect, find out the best parameter of blowing. Thenconduct the experiment. Numerical simulation results show that the double slot plugs in1/2the ladlebottom radius of45degrees is distributed symmetrically, molten steel flow field in the molten poolis best, dead zone proportion is smallest; Argon flow rate in the range of60m3/h to100m3/h, thesurface of molten steel flow is stable, argon stirring power utilization is better, the molten pool deadzone in the smaller percentage. The experimental results show that the bottom powder injectionsystem, application of liquid steel carburizing, because of the experimental equipment andexperimental operation conditions and immature conditions, carbon average yield can reach morethan70%, to further determine the bottom powder injection in carburizing process feasibility.