三、影响疲劳裂纹扩展的一些因素 如前所述,影响疲劳裂纹扩展的因素很多,其中主要的有显微组织、平均应力和介质环境等,这些因素对裂纹扩展各阶段的影响程度也有所不同,参看前面图5。以下对上述三个主要因素作一简要的评述。 Third, some of the factors that affect the fatigue crack growth As mentioned earlier, there are many factors that affect the fatigue crack growth, which are the main microstructure, the average stress and the media environment, these factors have different degrees of influence on the crack propagation stages are also different See Figure 5 above. The following is a brief review of the three major factors.