Decarburization Behavior of Molten Steel Using Top-blown Oxygen Jet under Reduced Pressure

In steelmaking, the top-blown oxygen jet is used in refining processes and its behavior is therefore an important factor for decarburization and spitting behavior of molten metal in steel refining. Numerous studies have been conducted on decarburization and spitting behavior with top-blown oxygen under atmospheric pressure conditions; however, the behavior under reduced pressure for vacuum refining processes is still not fully understood. In this study, decarburization and spitting behavior with top-blown oxygen under reduced pressure was investigated by small-scale experiment. Decarburization rate in oxygen supply-controlling region increased as the ambient pressure decreased. Also, total amount of spitting in decarburization increased as the ambient pressure decreased. These results can be explained by the attenuation rate parameter, AR, calculated from the top-blown oxygen and ambient pressure conditions.