Effect of slab width on choice of appropriate casting speed in steel production

Abstract

In steel continuous casting (CC), the choice of the appropriate speed at which the slab is cast can be influenced by many different factors and phenomena. While the slab thickness seems to have the biggest impact, other features like the slab width have been consistently overlooked. In fact, the slab width practically limits the casting speed via the mass flow constraint which governs the input and output balance at the tundish. Here, we present a case study that aims at analyzing steel production data from the perspective of casting speed constraints. By studying the speed fluctuations of an industrial CC machine, we identify a strategic regime change toward a stricter consideration of the mass flow constraint. The regime change manifests itself in a significant increase in the correlation between the actual casting speed and the maximal speed associated with the mass flow constraint. On the surface, taking greater account of the input and output balance at the tundish has reduced the productivity of the continuous caster; however, one can argue that the lessened yield is compensated by a diminished risk of eventual slab breaking. From the perspective of this trade-off, we establish a visualization technique that enables us to pinpoint the boundary beyond which one strategic regime becomes economically more advantageous than the other.