关键词: 初始不连续状态, 铝合金, 腐蚀损伤, 裂纹扩展, 腐蚀坑

Abstract: Corrosion experiment is performed for aviation LY12 aluminum alloy with imitating service environment of the military airplane. The fatigue life data for both uncorroded and pre-corroded LY12 aluminum alloy specimens are obtained after corrosion damage tests. The corrosion effects on LY12 aluminum are analyzed. Several predictive models are presented to calculate the fatigue life by measured value of pit size, and these predictive models of pitascrack are based on the initial discontinuity state (IDS). The calculated results of several predictive models based on IDS and straight pitascrack model are contrasted with experimental date. The results show that the calculated results of predictive models based on IDS agree reasonably with the experiment results, and the pitascrack directly is unreasonable. With the increment of pit size, the model 2 is more reasonable. It may be necessary to use different predictive models rather than a single predictive model to describe the corrosion pit.

Key words: initial discontinuity state, aluminium alloy, corrosion damage, crack growth, corrosion pit