Hot rolling - Rolling theory

As with most other metallurgical techniques, we knew how to roll long before there was even an outline of a theory to explain why we could roll. Nevertheless, rolling has been, and continues to be, the subject of a considerable amount of work. Some aim at a more advanced understanding of the thermomechanical phenomena of the rolling mill-product system; others are more prosaically concerned with solving more immediate problems that arise on the machine. It is the convergence of these two approaches that has led to real progress.

Why theoretical models? To understand how metal flows through an air gap, which can be geometrically complex. But above all, to predict the evolution, during deformation, of parameters that are important for product quality, or for the operation of the rolling mill; in short, to be useful to the engineer in developing the best product at the lowest cost.