文摘
The dynamic recrystallization (DRX) behavior of a medium carbon Cr-Ni-Mo alloyed steel 34CrNiMo was studied in the wide temperature range of 900–1150 °C and the strain rate of 0.002–5 s−1. Based on relations between the strain hardening rate and stress, the characteristic points, including critical strain (εc), critical stress (σc), peak strain (εp), peak stress (a1f" title="Click to view the MathML source">σp), were determined from the strain rate hardening versus stress curves. The Avrami equation was developed to model the kinetics of DRX, whereas the characteristic points can be expressed as a function of Zener-Hollomon parameter. Then the austenite grain size of DRX was measured by metallography and found to be a power law function of Zener-Hollomon parameter with an exponent of −0.2013. Besides, a mesoscopic cellular automaton model has been established to simulate the austenite DRX for the tested steel. This model was verified by means of the kinetics and topology of DRX.