The single-pass compression experiment of Q345GJC steel ( /% : 0.16C

0.36Si

1.37Mn

0.026Nb ) is carried out by Gleeble-2000 thermal simulator

the deformation resistances of tested steel with strain rate 0.1 ~ 1 s

-1

and true strain 0.8 ~ 1.2 at 900 ~ 1150℃; has been measured

and the influences of difierent process parameters on dynamic recrystallization and deformation resistance of tested steel are analyzed. The activation energy of dynamic recrystallization in peak state and steady state determined are respectively 245. 448 kj/mol and 166. 994 kj/mol

and the mathematical model of high temperature deformation resistance of tested steel is established. The model has good curve-fitting performance

its expected values close to the actually measured ones.