Reoxidation behavior in Al killed steel during casting

The kinetics of reoxidation of Al killed steel with slag and air were inves tigated in laboratory experiments using tammann furnace and in plant experi ments using commercial 85 x 10(3) kg tundish. Experimental results were dis cussed by the coupled reaction model. Observed apparent rate constants of [sol.Al] decreased with increasing (CaO )/(SiO2) ratio in laboratory experiments and showed a good agreement with c alculated ones. Flow rate of air leak at steady state was evaluated to be 3.0 x 10(-5) and 4.0 x 10(-4) m(3)/s inside and outside of immersion tube in commercial tund ish, respectively and was estimated to have little influence on reoxidation . Mass transfer coefficient in metal was estimated to be 6.0 x 10(-5) m/s bas ed on the tundish mixing model and the coupled reaction model. Observed [sol.Al] in tundish decreased with increasing (%FeO)+(%MnO) value in ladle slag and showed a good agreement with calculated one by considerin g reoxidation in ladle and air leak at unsteady state.