CHARACTERISTICS OF DECARBURIZATION REACTI ON BY COMBINED OXYGEN BLOWING IN HIGH-CARBON RANGE OF STAINLESS-STEEL MELTS

From the results of the experiments using a 100kg induction furnace an d a 60ton AOD, it was found that efficiency of decarburization with th e combined blowing became larger than that with the top blowing or the bottom blowing. It was suggested that the formation and reduction of (Cr2O3) in the hotspot with high temperature have influenced on decarb urization reactions. The decarburization potential by chromium-oxide ( CRP) was definded as the sum of the discrepancy (-Delta G)from decarbu rization reaction equilibrium by (Cr2O3) in hotspot and bulk of metal, and experimental results were evaluated by using CRP. There were good correlations between efficiency of decarburization and the value of C RP in every oxygen blowing types. The decarburization rate was control led by the balance of oxygen blowing rate and rate of carbon supply an d conditions of reaction zone, and the decarburization by combined blo wing with hard top blowing was promoted by the reduction oi (Cr2O3) in hotspot region.