预腐蚀后拉伸超载对LC4CS铝合金疲劳性能的影响

采用预腐蚀后进行单次拉伸超载疲劳试验的方法，研究了腐蚀与超载对LC4CS材料疲劳寿命的影响。结果表明，如果保持超载比不变，试件疲劳寿命将随预腐蚀年限增加而线性降低，且分散性逐年增大；在低超载比时，预腐蚀对疲劳寿命的亏损作用与超载对疲劳寿命的增益作用相互抵消；在超载比较大时，超载迟滞效应对疲劳寿命的增益作用明显。

Influence of Tensile Overload on Fatigue Life of LC4CS Al-alloy After Corrosion

Having undergone accelerative calendar corrosion,a plate with a central hole of LC4CS alloy was subjected to constant amplitude cyclic loads after a tensile overload.From such an experiment,two points could be studied: the interaction between corrosion and overload,and the contribution of this interaction to fatigue life.The analysis of experiment data showed that when overload-ratio was fixed,the logarithm fatigue life of specimen linearly descended with the increase of corrosion degree,and the dispersion increased.For small overload-ratio,the contribution of corrosion and overload to fatigue life approximately canceled out.But for large overload-ratio,overload retardation notably prolonged fatigue life and corrosion before overload seemed to amplify the prolonging.