吴护林,罗来正,刘春苗,赵方超,王彬,王键坤,刘溅洪,符朝旭.高强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对比研究[J].表面技术,2023,52(10):220-228.
WU Hu-lin,LUO Lai-zheng,LIU Chun-miao,ZHAO Fang-chao,WANG Bin,WANG Jian-kun,LIU Jian-hong,FU Zhao-xu.Comparative Study on Corrosion Damage Behavior of High Strength Aluminum Alloys under Synergistic Effect of Marine Atmospheric Environment and Tensile Fatigue Load[J].Surface Technology,2023,52(10):220-228 |
| 高强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对比研究 |
| Comparative Study on Corrosion Damage Behavior of High Strength Aluminum Alloys under Synergistic Effect of Marine Atmospheric Environment and Tensile Fatigue Load |
| 投稿时间：2022-10-29 修订日期：2022-12-20 |
| DOI：10.16490/j.cnki.issn.1001-3660.2023.10.017 |
| 中文关键词: 高强铝合金 协同作用 海洋大气环境 拉伸疲劳载荷 失效机理 |
| 英文关键词:high strength aluminum alloy synergistic effect marine atmospheric environment tensile fatigue load failure mechanism |
| 基金项目:国家自然科学基金(51901096);装备预研基金(80904020507);国防技术基础项目(HDH59030102) |
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| Author | Institution |
| WU Hu-lin | Southwest Institute of Technology and Engineering, Chongqing 400039, China |
| LUO Lai-zheng | Southwest Institute of Technology and Engineering, Chongqing 400039, China;School of Chemistry & Chemical Engineering, Chongqing University, Chongqing 400030, China |
| LIU Chun-miao | School of Chemistry and Materials Science, Ludong University, Shandong Yantai 264025, China |
| ZHAO Fang-chao | Southwest Institute of Technology and Engineering, Chongqing 400039, China |
| WANG Bin | School of Chemistry and Materials Science, Ludong University, Shandong Yantai 264025, China |
| WANG Jian-kun | Southwest Institute of Technology and Engineering, Chongqing 400039, China |
| LIU Jian-hong | Southwest Institute of Technology and Engineering, Chongqing 400039, China |
| FU Zhao-xu | Wanning Atmospheric-Material Corrosion Field-National-Observation and Research Station, Hainan Wanning 571522, China |
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| 中文摘要: |
| 目的 对比研究2024和7A52高强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特性，并揭示其失效机理。方法 以实际海洋大气环境作为高强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试样施加拉伸疲劳载荷，从电化学性能、腐蚀形貌、疲劳性能及断口形貌等方面对比分析协同效应下2种高强铝合金的腐蚀损伤规律。结果 在协同效应下，2024铝合金的腐蚀速率随着暴露时间的延长不断减小，腐蚀类型为剥蚀，最大腐蚀深度为236.4 μm。7A52铝合金的腐蚀速率随着暴露时间的延长呈现波动趋势，腐蚀类型为点蚀和晶间腐蚀，最大腐蚀深度为20.5 μm。2024铝合金相较于7A52铝合金更早出现腐蚀疲劳断裂，且2种合金的断口均呈现疲劳断裂特征，裂纹始于合金表面，在Cl−等腐蚀介质及拉伸疲劳载荷的协同作用下，裂纹不断向合金基体内部扩展，最终发生腐蚀疲劳断裂。结论 在协同效应下，2024铝合金的腐蚀速率及腐蚀损伤程度显著大于7A52铝合金，导致前者的抗疲劳性能弱于后者。 |
| 英文摘要: |
| As an ideal structural material in engineering, high strength aluminum alloy during service will suffer atmospheric corrosion, especially in the marine atmospheric environment, which will form a thin electrolyte film on the surface of aluminum alloy, and thin electrolyte film corrosion occurs due to the presence of corrosive media such as Cl−, O2, and SO2. In addition, during the service period, the high strength aluminum alloys as the structural materials are also subject to fatigue load. Thus, under the actual service conditions, the aluminum alloy structural materials endure the combined effects of atmospheric corrosion of thin electrolyte film and fatigue load. This work aims to comparatively study the corrosion damage behavior of 2024 and 7A52 high strength aluminum alloys under the synergistic effect of marine atmospheric environment and tensile fatigue load and to reveal the failure mechanism. The outdoor actual marine atmosphere in Wanning test site was used as the thin electrolyte film corrosion environment for alloy samples, and the self-designed fatigue load test device was utilized to apply tensile fatigue load at the same time. A sinusoidal stress waveform was employed to the sample with a frequency of 10 Hz. The stress ratio of the fatigue load was 0.1 and the maximum stress was 30% of the yield stress. Under such test conditions, the samples were subject to elastic deformation in a tension-tension mode. The fatigue load was applied once per month for 1 800 seconds. The corrosion damage law of the two kinds of alloys under the synergistic effect was comparatively analyzed based on electrochemical performance, corrosion morphology, fatigue performance and fracture morphology. The microstructure of 2024 alloy was characterized by a large number of irregularly shaped second phase particles and their surface distribution was not very homogenous. The grain boundary of 2024 was obvious and the grain was coarse, which was elongated along the rolling direction. Compared with 2024 alloy, the grain boundary of 7A52 alloy was less obvious, and the number and size of the second phase particles were significantly smaller than those of 2024 alloy, and thus the pitting and intergranular corrosion sensitivity of 7A52 alloy was significantly smaller than that of 2024 alloy. The corrosion rate of 2024 aluminum alloy decreased with the increase of exposure time under the synergistic effect. 2024 alloy suffered exfoliation corrosion and the maximum corrosion depth was 236.4 μm. The corrosion rate of 7A52 alloy fluctuated with exposure time. 7A52 alloy suffered pitting corrosion and intergranular corrosion and the maximum corrosion depth was 20.5μm. Compared with 7A52 alloy, 2024 alloy was subject to corrosion fatigue fracture earlier. The fractures of both alloys showed fatigue fracture characteristics. The cracks started from the surface of the alloys and continued to expand into the alloy matrix under the synergistic effect of Cl− and tensile fatigue load, and finally corrosion fatigue fracture occurred. Thus, it can be inferred that the corrosion rate and corrosion damage degree of 2024 alloy under the synergistic effect are significantly greater than those of 7A52 alloy, resulting in that the anti-fatigue property of the former is also weaker than that of the latter. |
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