EXPERIMENTAL INVESTIGATION AND MODEL SIMULATION OF MICROKINETICS OF NITROGEN TRANSFER BETWEEN IRON MELTS AND VACUUM

The present paper describes experiments on and model simulations of Th e microkinetics of nitrogen transfer between iron melts and vacuum. Ni trogen content is determined by pressure after Sieverts' law. It can b e reduced by the addition of elements such as aluminium, boron, niobiu m, and vanadium through nitride formation. The transfer of nitrogen at oms from the melt to the gas phase proceeds in three steps: the transf er of nitrogen atoms in the melt to the interface, the interfacial rea ction, and further transport of nitrogen molecules into the gas phase. Moreover, some essential experimental techniques are presented in thi s paper for studying the kinetics of nitrogen transfer. A modified Sie verts apparatus was used to investigate the nitrogen transfer between liquid iron melts and vacuum. (C) 1995 The Institute of Materials. Man uscript received 21 December 1994.