摘要
对具有粗、细晶粒组织的40CrNiMo 钢进行了疲劳短裂纹扩展试验研究。试验和分析结果表明,短裂纹扩展的偏折强烈,裂纹闭合效应较小。粗晶组织比细晶组织的裂纹偏折更大,粗糙度诱发闭合效应更强,因而裂纹扩展较幔。微观组织通过对闭合效应的作用进而影响了疲劳短裂纹的扩展行为。
The short fatigue crack growth behaviour for a Cr-Ni-Mo high strength steel with both coarse and fine grain structures was investigated in this experiment.The results turn out to be that the short cracks exhibit severe crack deflection and week crack closure effect.The short cracks deflect more severe in coarse grain structure than in fine grain one,result in roughness induced crack closure effect,therefore exhibit slow crack growth rate.The short fatigue crack growth behaviour was affected by the microstructure through its effect on crack closure.
基金
国家自然科学基金资助项目59171040
关键词
疲劳短裂纹
微观组织
裂纹闭合
microstructure
crack closure
short fatigue crack
