Empirically-based models are widely used throughout the industry to de
scribe the evolution of microstructure during the thermomechanical tre
atment of steel. There are growing demands for greater accuracy of pre
diction over a wider range of steel composition and operating conditio
ns. Both industry and universities worldwide are developing new models
to meet these demands. This paper reviews some of the key issues and
concludes that it is the development of physically-based models, tuned
with actual process data, that has the potential to satisfy this need
. (C) Munksgaard, 1998.