Theoretical and Experimental Research on the Mass Changes of Elements in Molten Steel with CO2 Used as RH Lifting Gas
CO2 injection into RH as lifting gas was recently proposed instead of Ar. In this study, FactSage software was used for calculating the mass changes of elements in thermodynamic equilibrium with CO2 injection under vacuum condition. Compared with Ar, CO2 as RH lifting gas can be used for a small amount of decarburization without a significant increase in oxygen content of molten steel. And the carbon content of alloys can be theoretically increased by more than 12% if all CO2 participates in the reaction between CO2 and [C]. Furthermore, the industrial application research of CO2 injection into RH as lifting gas was carried out in a commercial 150t RH. The results agreed with the above theoretical trends. And the problem of aluminum loss can be solved by reducing the additive amount of aluminum alloy in the ladle furnace (LF) and replenishing the aluminum during the RH refining later stage.
KeywordsCarbon dioxide RH refining Mass change Thermodynamic calculation Industrial test
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