1991 Volume 77 Issue 3 Pages 377-383
Kinetics of decarburization and oxygen absorption of molten iron of low carbon and oxygen concentrations has been studied. The decarburization and oxygen absorption experiments were performed by blowing Ar-O2 mixture (oxygen partial pressure 1.0×10-5<PO2(atm)<5.5×10-2 and gas-flow rate 1 000 (and 1 900) Ncm3/min) onto the melt surface. The rates of decarburization and oxygen absorption increase with increasing oxygen partial pressure ( PO2>1.0×10-2 atm). At oxygen partial pressures of PO2<1.0×10-4 atm, the oxygen concentration is kept almost constant. The total reaction rate of oxygen with the melt (=decarburization rate + oxygen absorption rate) is larger than the rate of oxygen absorption without decarburization and smaller than the rate calculated from a reaction model of oxygen diffusion in the gas phase. It is presumed that formation of oxide film on the melt surface has influence on the decarburization and oxygen absorption rates. A mathematical model is proposed to explain the rates of decarburization and oxygen absorption.
