Physical simulation of finish rolling of microalloyed steels in isothermal conditions

The aim of this work was to establish a temperature finish rolling stage Nb/Ti microalloyed steel containing 0.06 wt.% C, 0.77 Mn, 0.039 Nb and 0.015 Ti, using physical simulation. Samples were subjected laboratory simulation at twist plastometer high temperatures, i.e. between 825 950?C. Five pass deformation interpass times selected in accordance with processing parameters five stand finishing hot strip mill. Restoration (recovery and/or recrystallization) behavior evaluated by calculation Fraction Softening (FS) Area Parameter (ASP) values. At 950?C all individual stress-strain curves, FS ASP show full recrystallization intervals. On the other hand, decrease interval 875-825?C, extent restoration is decreasing, leading recovery as sole softening mechanism 825?C, which confirmed curve shape, values ASP. It assumed that, due supersaturation, strain-induced precipitation promoted pinning grain subgrain boundaries suppressed recrystallization. Therefore, critical for estimated be 825?C.