使用Gleeble-1500型热机械模拟机在变形温度900~1 100℃、应变速率0.01~10 s^-1下对Fe-10Mn-2Al-0.1C (质量分数/%)中锰钢进行热压缩试验,根据试验数据,采用应变补偿法建立试验钢Zener-Hollomon本构模型并进行了试验验证;基于动态材料模型(DMM)建立试验钢在真应变0.2,0.4,0.6,0.8下的热加工图。结果表明:由建立的本构模型预测得到的流动应力与实测应力的相关系数为0.987,说明该模型可用来描述试验钢的热变形行为;由本构模型计算得到当真应变从0.1增加到0.8时,试验钢的热变形激活能从476 kJ·mol^-1降低到342 kJ·mol^-1;根据热加工图确定试验钢的最佳热加工工艺条件为变形温度900~940℃、应变速率0.01~0.03 s^-1和变形温度1 070~1 100℃、应变速率0.1~0.56 s^-1,该条件下的功率耗散效率在32%~38%。

Hot compression tests at deformation temperatures of 900-1 100 ℃ and strain rates of 0.01-10 s^-1 were conducted on Fe-10Mn-2Al-0.1C (mass fraction/%) medium Mn steel by using a Gleeble-1500 thermo-mechanical simulator. The Zener-Hollomon constitutive model of the test steel was established by a strain compensation method with the test data, and verified by the tests. The hot processing maps of the test steel at true strains of 0.2, 0.4, 0.6, 0.8 were established on the basis of the dynamic material model (DMM). The results show that the correlation coefficient between the flow stresses predicted by the established constitutive model and the measured stresses was 0.987, indicating that the model can be used to describe the thermal deformation behavior of the test steel. According to the calculation by the constitutive model, when the true strain increased from 0.1 to 0.8, the hot deformation activation energy of the test steel was reduced from 476 kJ·mol^-1 to 342 kJ·mol^-1. According to the hot processing maps, the optimal hot working conditions of the test steel were determined as deformation temperatures of 900-940 ℃ and strain rates of 0.01-0.03 s^-1, and deformation temperatures of 1 070-1 100 ℃ and strain rates of 0.1-0.56 s^-1; the power dissipation efficiency under these conditions was 32%-38%.