| Abstract: | More recently, lower nitrogen contents of steel are required in view of its workability and applicability. The present study covers basic investigations on the improvement of mass transfer in denitrogenation of steel melts under vacuum. Extensive reduction of the contents of the surface-active elements oxygen and sulfur is a precondition to increase the rate of nitrogen desorption. Kinetics of nitrogen transfer is reliably described by a mixed control model which includes diffusion in the melt, interfacial reaction and diffusion in the gas phase. Particularly at low oxygen and sulfur contents, mass transfer of nitrogen during desorption from steel melts is markedly accelerated. A convincing explanation of this phenomenon has not been found yet. |
