模拟沿海大气环境腐蚀对2A12-T4 铝合金板件疲劳行为的影响

对航空材料服役的大气环境开展实验室加速模拟试验以获得其长期腐蚀行为和寿命退化情况是相关材料和装备设计、制造、维修以及寿命评定和寿命控制的重要内容和基础。通过开展针对2A12-T4 铝合金板件的模拟铝合金沿海大气腐蚀的实验室加速腐蚀试验,模拟研究从初期点蚀到后期剥蚀的整个沿海大气腐蚀过程中,腐蚀对铝合金板件疲劳特性的影响;基于疲劳寿命退化相当的原则,建立2A12-T4 铝合金板件加速腐蚀与大气腐蚀之间的加速等效关系。结果表明：2A12-T4 铝合金实验室加速预腐蚀后疲劳寿命退化规律与大气预腐蚀疲劳寿命退化规律一致,均呈现为“快速下降期”+“平台期”的特征。

The Effect of Coastal Atmospheric Corrosion on the Fatigue Characteristics of 2A12-T4 Aluminum Alloy Plate

This article conducts laboratory accelerated corrosion tests on simulated coastal atmospheric corrosion of 2A12-T4 aluminum alloy plates, simulating the impact of corrosion on the fatigue characteristics of aluminum alloy plates throughout the entire coastal atmospheric corrosion process from initial pitting to later erosion. Based on the principle of equivalent fatigue life degradation, an accelerated equivalent relationship between 2A12-T4 aluminum alloy plate accelerated corrosion and atmospheric corrosion is established. The research results show that the fatigue life degradation law of 2A12-T4 aluminum alloy after accelerated pre corrosion in laboratory is consistent with that of atmospheric pre Corrosion fatigue life degradation law, which is characterized by "rapid decline period"+"platform period". The first 144 hours of accelerated corrosion in the laboratory are approximately equivalent to the effect of corrosion on fatigue life in the first year of actual atmospheric environment; After 144 hours, every 36 hours of accelerated corrosion (3 cycles of immersion) is approximately equivalent to the effect of 2 years of corrosion on fatigue life in actual atmospheric environments.