Abstract: The isothermal single-stage compression of 35CrMo stuctural steel has been carried out by using Gleeble 1500 simulator at the temperature range of 950℃ to 1150℃ and strain rate range of 0.01s^-1 to 10s^-1.The effect of hot deformation parameters,such as strain rate,deformed temperature and initial grain size on the flow stress behavior was investigated.The activation energy of tested alloy was calculated,which is 378.16kJ/mol;The relationships between the peak stress(σp),the peak stain (εp),the critical strain(εc)and Z parameter were established.The microstructure evolution shows the pre-existing austenite grain boundaries constitute the principal nucleation sites for dynamic recrystallization (DRX),and the initial austenite grain size affects the grain size of DRX slightly.The kinetic mathematical model of DRX of 35CrMo is:XDRX=1-exp(-3.23·(ε-εc/εs-εc)^2.28)and Ddyn=2.252×10^4Z^-0.22。

Key words: dynamic recrystallization, deformation activation, energy,