10Ni8CrMoV钢热影响区的动态力学特征及其本构模型

Dynamic Mechanical Characteristics and Constitutive Model of the 10Ni8CrMoV Steel HAZ

使用热模拟试验机获得10Ni8CrMoV钢热影响区类似组织,通过霍普金森压杆试验对热影响区试样的动态力学行为进行表征,并观察其微观组织。结果表明:在高应变速率下,热影响区真实应力随着应变率的增加而增加,表现出明显的应变率强化效应;应变速率为2000 s^(-1)时,试样中出现大量的变形孪晶,应变速率为4000 s^(-1)时,试样被剪切破坏;基于Johnson Cook模型,得到10Ni8CrMoV钢热影响区动态本构模型。

Similar structures in the heat affected zone of 10 Ni8 CrMoV steel are obtained using a thermal simulation tester,and the dynamic mechanical behavior of the heat affected zone specimens are characterized by the Hopkinson Bar,and its microstructure are observed.The results show that under the high strain rate,the real stress of the heat affected zone increases with the increase of strain rate,showing obvious strain rate strengthening effect.At a strain rate of 2000 s^(-1),a large number of deformed twins appear in the specimen,and the specimen is sheared at a strain rate of 4000 s^(-1).Based on the Johnson-Cook model,a dynamic constitutive model of the heat affected zone of 10 Ni8 CrMoV steel is obtained.