CINÉTICA DA DISSOLUÇÃO DE PRECIPITADOS DURANTE O REAQUECIMENTO DE PLACAS DE AÇO MICROLIGADO

This work describes a mathematical model for the calculation of the solution kinetics of microalloying elements during steel slab reheating previous to hot rolling. That model shows that, under the industrial practical conditions of slab reheating, eutectoid precipitates with size greater than 250 nm are not completely dissolved, decreasing the free Nb content in austenite. It is also verified that the solution efficiency varies according to small oscillations in chemical composition of the microalloyed steels, a situation that is particularly important in the so called “skid marks” (colder regions) in the reheated slabs.