Characterization of hot deformation behavior of a low carbon steel using processing maps, constitutive equations and Zener-Hollomon parameter

Physical processes that occur during hot compression tests performed on AISI1010 steel in the temperature range of 750 °C–1050 °C and strain rates range of 0.01–20 s−1 are discussed using microstructural observations and are related to the stress-strain response. The apparent activation energy is 177 kJ/mol and the stress exponent is 3.5, which suggest that the deformation is controlled by dislocation glide and climb. Temperature rise due to deformation is considered in characterizing the flow softening behavior. Processing maps created using different models are discussed together with change in the Zener-Hollomon parameter (Z) in the domain of strain rates and temperatures. Z is related to the power dissipation efficiency, flow stress, and microstructural evolution. Lower values of Z promoted the restoration processes. Dynamic recrystallization is the primary restoration mechanism between 750 °C and 875 °C and in the 0.01–0.1 s−1 range, where highest power dissipation efficiency is observed.