A new interpretation of mechanisms of nitrogen desorption from liquid iron

Abstract

Mechanisms of nitrogen desorption from liquid iron were discussed in detail. It is proposed that association of nitrogen atoms at the surface to form a molecule occurs by two separate mechanisms operating in parallel: single site mechanism meaning that an adsorbed atom reacts with an atom coming from the bulk using one adsorption site, and dual site mechanism meaning that two adsorbed atoms diffuse to and react with each other over two adsorption sites, and that association via these two parallel mechanisms is rate controlling for the interfacial reaction of nitrogen desorption. A model for the second order rate constant of nitrogen desorption from liquid iron was theoretically derived, and was found to be in close agreement with the results reported in literature, for both normal pressure and reduced pressures.