Technologies for producing the ultra low carbon and nitrogen steel in RH degasser

Experimental and theoretical studies Here carried out to understand the behavior of carbon content and nitrogen content during RH treatment. A new model for decarburization was developed to estimate the decarburization rate and to predict the carbon content, This model clarified the effects of carbon content, oxygen content, argon gas Row rate, the pressure in the vessel and the cross section area of the vessel on the decarburization rate. With helium detection, it was found that air invaded in molten steel through the down leg snorkel. A new snorkel with argon sealed protected the air suction. and it made possible to produce the ultra low nitrogen steel.