筒形机匣连接凸耳疲劳寿命及其影响因素

分析了筒形机匣连接凸耳疲劳寿命的主要影响因素。结果表明，５个试验件凸耳组织的再结晶程度有很大的差别，正是由于凸耳组织再结晶程度的分散性导致了其疲劳寿命的分散性。进一步的分析表明，凸耳组织再结晶程度的分散性是由于模锻时材料原始晶粒大小和形变量不同造成的。此外，凸耳孔壁表面的加工缺陷也是降低凸耳疲劳寿命的一个重要因素。

An analysis on effective factors to fatigue lives of pull rod linking lugs of tube-shaped cases

The cause of the diversity of fatigue lives of linking lugs of five tube shaped cases was investigated by microfractography and metallography techniques. The recrystallization degrees of microstructure of lugs are much different. It is the diversity of recrystallization degrees that results in that of fatigue lives of lugs. The diversity of the recrystallization degrees may be resulted from the difference in deformation magnitude and original grain size of materials in die forging. In addition, another important factor of decreasing lives of lugs is machining defects in hole wall surfaces of lugs.