金属材料表面微裂纹萌生的概率分析

Probability analysis of initiation and growth of small surface cracks of metal materials

利用片状石墨铸铁ＨＴ２０－４０为对象并在应力控制条件下进行了低温和高温低周疲劳试验，应力波型选用Ｃ－Ｐ型（拉伸保持）和Ｃ－Ｃ型（拉压保持）．采用晶界破坏阻抗模型对表面微裂纹萌生和扩展的随机行为作了分析和讨论，表面裂纹萌生时间和角度计算结果与实验相符合．

Low cyclic fatigue tests at elevated temperatures are carried out under stress-controlledcondition in air with stress waveforms of C-P type(tensile hold )and C-Ctype(tensile andcompressive hold)by graphite cast iron HT2O-40. The random behavior of initiation and growthof small surface cracks under creep-fatigue condition is analysed and discussed based on the grianboundary fracture resistance model.