Investigation on the Effects of Hot Rolling Process Parameters on the Oxide Structure for Automobile Beam Steel Strips

摘要

The structure of oxide scale is the major factor which directly affects the surface quality of the hot rolled strip and the succeeding process. Oxidation kinetics and thermal simulation experiments were conducted to investigate the effects of process parameters on the structure of oxide scale for hot rolled Nb micro-alloyed motor beam steel strips. It has been suggested that oxide gain increased linearly with time at 700℃ while increased parabolically with time above 800℃. The evolution of oxide scale from finish rolling to coiling was simulated. Results have shown that the proportion of Fe3O4 in oxide scale increases gradually with the increasing of start rolling temperature. The thickness of Fe3O4+ FeO layer gradually decreased with increasing of finish rolling temperature. And the proportion of Fe3O4+FeO layer increased with the decreasing of coiling temperature.