Mathematical Simulation of Behavior of Carbon and Oxygen in RH Decarburization

A mathematical model for RH decarburization was developed on the basis of the principle of carbon and oxygen balance. In the simulation, a physical description of the different reaction sites associated with the different mechanisms was considered. Furthermore, the oxygen transfer between top slag and molten steel was also considered. The calculated results of the model were in good agreement with the operation data of the two different plants. The model was applied to analyze the effect of KTB starting time on the RH decarburization rate for ultra-low carbon steel production using slag reforming or LF refining. According to the results, the RH decarburization rate especially the inner site decarburization rate is controlled by the KTB starting time. In actual operation, late KTB starting time should be avoided.