Advanced high-strength steels (AHSS) typically have much higher aluminium concentrations (by an
order of magnitude or more) than conventional low-carbon aluminium-killed steels. The resulting
lower oxygen activity at the steel-slag interface changes the kinetics and thermodynamics of steelslag
reactions. Previous work showed that the rapid transformation of alumina inclusions to spinel
inclusions, and spinel to periclase, occurs because of the relatively high concentration of dissolved
magnesium. In this paper, experimental results on nitrogen removal by ladle slag are compared with
predictions based on the available thermodynamic databases. As in previous work, the kinetics was
modelled by assuming mass transfer control, with steel or slag mass transfer limiting. The results
show that significant removal of nitrogen by steel-slag reaction is possible.