目的 研究不同应力加载条件对7050铝合金在海洋大气环境与拉伸疲劳载荷协同作用下的腐蚀损伤行为的影响规律。方法 以实际海洋大气环境为7050铝合金的薄液膜腐蚀环境，同时采用自主研发的疲劳载荷试验装置对暴露在海洋大气环境中的7050铝合金施加不同的拉伸疲劳载荷。研究应力比和载荷加载周期对协同作用效应下7050铝合金的腐蚀速率、腐蚀形貌、疲劳性能及断口形貌等的影响规律。结果 在海洋大气环境与拉伸疲劳载荷协同作用下，所有7050铝合金试样均发生了点蚀和晶间腐蚀。在每月加载1次应力的条件下，应力比为0.1和0.06的试样的最大腐蚀深度分别为40.1、46.5 μm。在每周加载1次应力的条件下，试样的最大腐蚀深度为41.2 μm。每周加载应力、应力比为0.06的试样的腐蚀速率显著大于应力比为0.1、每月加载应力的试样的腐蚀速率，且前者更易发生腐蚀疲劳断裂。所有试样的断口都呈现出疲劳断裂特征，裂纹源在合金表面，并放射性地向试样芯部扩展。结论 缩小应力加载周期及减小应力比均会显著加速协同作用效应下7050铝合金的腐蚀损伤进程，降低其抗疲劳性能。

As the structural material of the marine equipment superstructure, the corrosion damage behavior of high strength aluminum alloy can be attributed to the interaction of thin electrolyte film corrosion of marine atmospheric environment and fatigue load. At present, researches on the interaction between corrosion environment and fatigue load mainly focus on corrosion fatigue crack propagation and fatigue life, and the corrosion condition is mainly solution immersion environment. However, atmospheric corrosion is carried out in a thin electrolyte film. The development of the corrosion process and its secondary effects and the affecting factors of which are very different from those in the solution. This work aims to study the effect of different stress loading conditions on the corrosion damage behavior of 7050 aluminum alloy under the synergistic effect of marine atmospheric environment and tensile fatigue load. The outdoor actual marine atmosphere in Wanning test site was used as the thin electrolyte film corrosion environment for 7050 alloy, and the self-designed fatigue load test device was utilized to apply different tensile fatigue loads at the same time. A sinusoidal stress waveform was employed to the specimen with a frequency of 10 Hz, and the maximum stress was 30% of the yield stress. The stress ratios of the fatigue load were 0.1 and 0.06. The stress loading periods included two ways:one was to load the stress once a month for 1 800 s each time; the other was to load the stress once a week for 450 s each time. It intended to study the effects of stress ratio and stress loading period on the corrosion rate, corrosion morphology, fatigue property and fracture morphology of 7050 alloy under the synergistic effect. The microstructure of 7050 alloy was characterized by a spot of irregularly shaped second phase particles and their surface distribution was not very homogenous. The grain boundary morphology of 7050 alloy was flat, and the grain was elongated along the rolling direction. All 7050 alloy specimens suffered pitting corrosion and intergranular corrosion under the synergistic effect of marine atmospheric environment and tensile fatigue load. The corrosion product layers of specimens under the dynamic stress condition were less compact and had many superficial cracks on them. Under the condition of loading stress once a month, the maximum corrosion depths of specimens with 0.1 stress ratio and 0.06 stress ratio were 40.1 μm and 46.5 μm, respectively, while the maximum corrosion depth of specimens with stress loaded weekly was 41.2 μm. The corrosion rates of specimens loaded monthly and with 0.06 stress ratio were significantly higher than those of specimens loaded monthly and with 0.1 stress ratio, and specimens in the former case were more prone to corrosion fatigue fracture. The fractures of all specimens showed fatigue fracture characteristics. The crack sources were located on the surface of the alloys and propagated radioactively to the core. Thus it can be inferred that the decrease in the stress loading period and stress ratio will significantly accelerate the corrosion damage process of 7050 aluminum alloy under the synergistic effect and reduce its anti-fatigue performance.