Interpass recrystallization of austenite in some steels during rolling

AbstractVarious steels were rolled using several passes, and the resulting microstructures, precipitation of AlN and NbC, and mechanical properties were investigated. Below a certain critical temperature, interpass recrystallization does not occur completely following the first pass. The volumefraction of unrecrystallized austenite initially increases rapidly, but then decreases gradually as the rolling temperature is lowered. The amount of AlN and NbC precipitation does not appear to be related to the fraction of unrecrystallized austenite. It is proposed that the cause of incomplete recrystallization is the recovery substructure present in austenite grains which, because of their coarse size, do not recrystallize after the first pass. The incomplete interpass recrystallization produces a duplex microstructure, giving the steel a deformation anisotropy.