采用Gleeble-1500型热模拟试验机对60钢进行不同温度(730,750,800,850,900,1 000℃)和不同应变速率(0.01,0.1,1,5,10 s^-1)的热压缩试验,总真应变为0.8,分析了60钢在热压缩过程中的变形行为;引入变参数Arrhenius模型,采用五阶多项式对模型中各参数随应变的变化关系进行拟合,构建出60钢高温变形本构方程,并对方程的精确性进行了评估。结果表明:变形温度越高,应变速率越低,60钢的流变应力越小;在较低温度和较高应变速率下,60钢热压缩变形的软化机制主要为动态回复,在较高温度和较低应变速率下则主要为动态再结晶;建立的变参数Arrhenius本构方程对流变应力的预测值与试验值的拟合相关系数达到0.994 597,说明该本构方程可以较好地描述60钢的高温变形行为。

Hot compression tests were carried out on 60 steel at different temperatures (730, 750, 800, 850, 900, 1 000 ℃) and different strain rates (0.01, 0.1, 1, 5, 10 s^-1) with a Gleeble-1500 thermal simulator; the total true strain was 0.8. The deformation behavior of 60 steel during the hot compression process was analyzed. A variable parameter Arrhenius constitutive model was introduced. The relationships between the parameters of the model and the strains were fitted by a fifth-order polynomial, and then the constitutive equation for high temperature deformation of 60 steel was established. The accuracy of the equation was evaluated. The results show that the higher the deformation temperature or the lower the strain rate, the lower the flow stress of 60 steel. At lower temperatures and higher strain rates, the softening mechanism of hot compression deformation of 60 steel was mainly dynamic recovery; at higher temperatures and lower strain rates, it was mainly dynamic recrystallization. The fitting correlation coefficient between the predicted flow stresses by the established variable parameter Arrhenius constitutive equation and the experimental values was up to 0.994 597, indicating that the constitutive equation could describe the high temperature deformation behavior of 60 steel well.