潮湿空气环境对2024-T3铝合金疲劳性能的影响

采用2024-T3铝合金含中心孔试件进行了实验室空气环境和潮湿空气环境下的疲劳寿命实验及升降法实验,研究了潮湿空气环境对2024-T3铝合金疲劳性能的影响.结果表明,潮湿空气环境显著降低了2024-T3铝合金的疲劳性能,潮湿空气环境对其疲劳寿命特征值和疲劳强度均值的影响系数分别为0.6059和0.8722;在潮湿空气环境中疲劳寿命的分散性变大,用疲劳寿命的中值或特征值得到的腐蚀影响系数进行可靠度95%的腐蚀环境下的寿命修正,将得到偏危险的结果.用潮湿空气环境对基本可靠性寿命的影响系数由标准S-N曲线折算得到的对疲劳强度的影响系数与升降法测得的对疲劳强度的影响系数基本一致,在潮湿空气环境下标准S-N曲线参数仍然适用.

The influence of wet air on fatigue performance of 2024-T3 aluminum alloy

Fatigue life and staircase experiments with center-hole specimens in laboratory air and wet air environment were conducted to investigate the corrosion influence of wet air on fatigue performance in 2024-T3 aluminum alloy. The results show that wet air reduces both fatigue life and strength with the influence-factor of 0.6059 and 0.8722, respectively. Wet air environment enlarges the dispersivity of fatigue life, therefore using the corrosion-influence-factor obtained by eigenvalue or mean value to predict the fatigue life with high reliability will cause an unconservative conclusion. The corrosion-influence-factor of fatigue strength converted from that of fatigue life by stantard S-N curve is almost the same with that gained by staircase experiments. It indicates that the existing stantard S-N curve parameters are applicable in wet air environment .