Processing of microalloyed steel for automotive applications on a thin slab plant

The use of thin slab casting and direct rolling is well suited for the production of hot and cold rolled strip from Niobium microalloyed low-carbon high strength steel grades. Thermomechanical processing by controlling hot work hardening and softening processes of austenite and its polymorphic transformation into ferrite results in a powerful microstructure refinement. This is a sound basis for producing high strength hot strip, combined with excellent ductility and toughness. Hot strip from thin slab plants can easily be further processed to cold rolled and surface treated cold rolled strip. However, special care has to be taken to meet particular surface quality requirements for automotive applications. (AU)