Rates of Nitrogen and Carbon Removal from Liquid Iron in Low Content Region under Reduced Pressures.

The kinetics of nitrogen and carbon removal from a liquid iron surface in low content regions by blowing Ar gas mixture under reduced pressures have been studied using the samevacuum induction furnace at 1 6000c, respectively.The results obtained are as follows:(1)The nitrogen removal reaction is described as a second order reaction with respect to nitrogen content.The overall reaction rate constant, k~v' decreases with the increase of total pressure.and oxygen and sulfur content.Assumingthat the nitrogen removal reaction progresses by a mixed control and that the chemical reaction for nitrogen gas formation is caused by adsorbed nitrogen atoms, the chemical reaction rate constant, k~ and the adsorption coefficient of oxygen.,(o, and of sulfur, 1(s, are estimated as follows:,(s=63.4In the Fe-20masso/oCr-0.2massoloC-Ssystem also, the value of k~c an be expressed by the same equation.It is thus concluded that, macroscopically, the mechanismof nitrogen removal is the same irrespective of whether or not the melt contains chromium.exf2jlits I ~aex: amrubomnvcaoluneteangtarlannsgt eo~ye:oewnc200~tePnPtm, ~;hdedoevcerreaal:ecsarwboltnh :ehmeoj ~vca!eraesaect:of ns Jalftuer ccoonnstteanntt., k~v'Assuming that the chemical reaction for COgas formation caused by the adsorbed carbon and the adsorbed oxygen atoms as a following equation, the dependenceof the chemical reaction rate constant on oxygen andsulfur content is explained by the values of the adsorption coefficients ,(o and rcs.respectively. E,+1~l=L~~I +]The value of Ko is equal to about I O0-300and that of ,cs is equal to about 40-65.These values are in general accord with those determined from the nitrogen desorption reaction.