摘要: It is shown that the average O in the steel can be decreased to 12.86 ppm and there is an optimal %Si at the end of melting as 0.11%, at which O after vacuum carbon deoxidation （VCD） is minimum. A kinetical model has been deduced to simulate the VCD process. The results show that adding Si before Al is superior to the adding Al before Si with respect to the final O in the steel. It is suggested that the melting point of covering slag should be lower than 1550℃, and （FeO+MnO） should be less than 1%, so as to effectively refine GCr15 steel.