16Mn钢锐缺口疲劳裂纹萌生寿命研究

以16Mn钢为研究对象,通过带缺口试样的疲劳试验得到不同尺寸的缺口启裂时所对应的疲劳循环次数,回归得到16Mn钢的缺口启裂寿命估算公式。然后采用与真实焊缝咬边等尺寸的模拟试样,进行与实际结构等应力范围条件下的模拟疲劳试验,并结合通过应力-寿命法得到的结果进行分析比较。结果表明,试验寿命与根据估算公式计算得到的寿命非常接近,应力-寿命法得到的结果偏保守,从而为带锐缺口的在用压力容器疲劳寿命评估提供理论依据和试验数据。

Research initiation life of the sharp notch in 16Mn-steel

16Mn-Steel was chosen for testing the corresponding fatigue cycle-index for notch crake with different sizes obtained through fatigue test for notch specimen.After regression,an estimation formula for crack initiation life was deduced.Then a simulation fatigue test is performed by using the samples with the same size as the real undercuts,as well as the simulating fatigue test under the stress range of the actual structure,which will be compared with the results obtained according to the S-N approach.As a result,the estimating life according to the formula approaches is close to the experimental life.Thus the results obtained through the S-N approach are conservative,which provide theoretical basis and experimental date for the life evaluation of pressure vessel.