Effect of rolling in the intercritical region on the tensile properties of dual-phase steel.

A steel containing 0.088 wt% C, 1.2 wt% Mn, and 0.78 wt% Cr was rolled at intercritical temperature (790 °C) and quenched to produce dual-phase microstructure. Rolling caused anisotropic increase in tensile strength and little change in ductility. The results suggest that rolling increased strength by a combination of strengthening of the ferrite and an increase in the stress transferred to the martensite. Up to 20% rolling reduction strengthened the ferrite by work hardening, larger reductions then reduced the strength of ferrite, anisotropically, due to increased recovery. Subgrains in ferrite were observed after rolling in the intercritical region which can contribute to the ultimate strength of the rolled material. [ABSTRACT FROM AUTHOR]