Abstract: 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.

摘要： 利用Gleeble-2000热模拟试验机对Q345GJC钢（/%:0.16C,0.36Si,1.37Mn,0.026Nb）进行了单道次压缩试验,实测了试验钢900～1 150℃、真应变0.8～1.2、应变速率0.1～1 s^-1的变形抗力,分析了各工艺变形参数对试验钢动态再结晶和变形抗力的影响。确定了试验钢的动态再结晶激活能为245.448 kJ/mol（峰态时）和166.994 kJ/mol（稳态时）,并建立了试验钢高温变形抗力的数学模型。该模型具有良好的曲线拟合特性,用该模型计算的结果与实测值吻合较好。

关键词: 高层建筑用钢Q345GJC, , 动态再结晶, 变形抗力, 热模拟试验, 数学模型