Hot deformation behavior of a medium carbon microalloyed steel

The hot deformation behavior of a medium carbon microalloyed steel was studied using the hot compression flow curves corresponding to the temperature range of 850–1150 °C under strain rates from 0.0001 to 3 s−1. A step-by-step procedure for data analysis in hot deformation was also given. The work hardening rate versus stress curves were used to reveal if dynamic recrystallization (DRX) occurred. The application of constitutive equations to determine the hot working constants of this material was critically discussed. Furthermore, the effect of Zener–Hollomon parameter (Z) on the characteristic points of flow curves was studied using the power law relation. The deformation activation energy of this steel was determined as 394 kJ/mol and the normalized critical stress and strain for initiation of DRX were found to be 0.89 and 0.62, respectively. Some behaviors were also compared to other steels.

Research highlights
► Hot compression test under a wide range of temperature and strain rate.
► A step-by-step procedure for data analysis in hot deformation.
► Critical discussion on the application of constitutive equations.