从压力容器的实际工况和抗震安全性设计出发,对Q345R钢进行低周、超低周疲劳试验。在MTS-809疲劳试验机上进行试验,采用轴向恒应变控制方法;获得其典型迟滞回线及低周、超低周循环应力-应变曲线,与拉伸应力-应变关系比较得出Q345R钢为循环硬化材料;开展回归分析,确定了材料的疲劳特性参数及应变-寿命曲线。为压力容器抗震设计、疲劳寿命预测提供依据。 Based on the actual conditions of the pressure vessel and the design of seismic safety, low-cycle and ultra-low cycle fatigue tests on Q345R steel are carried out. In the MTS-809 fatigue testing machine test, the use of axial constant strain control method; access to its typical hysteresis loop and low cycle, low cycle stress-strain curve, and tensile stress - strain relationship obtained Q345R steel Cyclic hardened material; carried out regression analysis to determine the fatigue properties of the material parameters and strain - life curve. It provides the basis for the seismic design of pressure vessel and prediction of fatigue life.