Nitrogen Alloying of Carbon and Stainless Steels by Gas Injection

A model of nitrogen alloying of carbon or stainless steels by bottom nitrogen gas injection in converters or ladles has been developed. It combines a description of the local kinetics in terms of a mixed-control interfacial reaction/liquid-phase mass transfer model and a hydrodynamics description of the plumes that constitute the active reaction zones. It has been valid ated from special trials made in the converter and ladle at atmospheric pressure or under vacuum for carbon steels and in the ladle for stainless steels with ultra high N contents.