The fatigue and pre -corrosion fatigue performance test of LY12CZ sheet samples was introduced. The micro and the macro morphologies of the fracture are studied. The effect of different pre- corrosion time on the fatigue performance of LY12CZ is analyzed.The experiment shows that the fatigue life of LY12CZ reduces as the corrosion degree goes higher. After 5h, 24h, 168h and 216h, the fatigue life of the sample decreases by 84.5％, 92.8％, 98.8％ and 98.8％ irrespectively; in comparison with the original material,with the slightly corroded sample, the number of fatigue crack sources on the fracture is smaller, and the embryonic zone of crack and the crack extension zone is larger; with the highly corroded sample, the number of fatigue crack sources is larger, and both the embryonic zone of crack and the crack extension zone are smaller.%用LY12CZ板材加工的试样分别作疲劳性能和预腐蚀疲劳性能实验,对试样的断口进行了宏观和微观的形貌观察,分析了预腐蚀不同时间对LY12CZ试样疲劳性能的影响.实验结果表明,随着腐蚀程度的加深,LY12CZ的疲劳寿命降低.预腐蚀5h,24h,168h,216h时后的试样疲劳寿命比未腐蚀的疲劳寿命分别下降了84.5%、92.8%、98.8%、98.8%.;腐蚀较轻的试样,断口上疲劳裂纹源数量较少,裂纹萌生区和裂纹扩展区较大;腐蚀程度较重的试样,疲劳裂纹源数量较多,裂纹萌生区和扩展区均较小.
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