复杂应力状态225Cr 1Mo钢的高温低周疲劳裂纹扩展规律

 用带预裂纹的缺口试件研究225Cr 1Mo 钢高温低周疲劳裂纹扩展规律，通过疲劳试验观察裂纹扩展寿命，应用ANSYS计算裂纹尖端应力应变分量和当量弹、塑性应变范围，利用当量J积分范围表征225Cr 1Mo 钢在复杂应力状态下的低周疲劳裂纹扩展速率。结果表明：疲劳裂纹扩展速率da/dN与当量J积分范围ΔJf的关系不受试件缺口型式和加载应变范围的影响，用当量J积分来评价225Cr 1Mo 钢的高温低周疲劳裂纹扩展规律是有效的。

High Temperature Low Cycle Fatigue Crack Propagation of 225Cr 1Mo Steel in Complex Stress State

The crack propagation law of 225Cr 1Mo steel was researched with notched cylinder specimen under the condition of high temperature low cycle fatigue. The crack propagation life was viewed by fatigue experiment and the equivalent stress strain on the crack tip was calculated by the ANSYS. The equivalent J integral range which was computed by equivalent elastic and plastic strain ranges was employed to denote the fatigue crack propagation rate. The results showed that crack propagation law of this material in complex stress state can be characterized by equivalent J integral ranges and the relation between da/dN and ΔJf is not influenced by the type of notch and the load strain range.