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典型腐蚀环境下的疲劳性能是航空金属结构疲劳寿命设计的前提,为此,实验测定航空铝合金2E12-T3和7050-T7451光滑试样和缺口试样在干燥大气环境和油箱积水环境下的疲劳性能S-N曲线,观测实验现象,根据实验数据结果进行疲劳性能对比,并对试样断口进行扫描电镜(SEM)分析,研究油箱积水腐蚀环境和载荷联合作用对疲劳性能的影响机理,结果表明:油箱积水环境对材料的疲劳性能产生不利影响,疲劳载荷的降低和试样的缺口均加剧腐蚀环境对材料疲劳性能的不利影响;腐蚀引起的试样表面粗糙状况更容易萌生疲劳裂纹,裂纹尖端发生的电化学反应和氢脆效应加快裂纹扩展,使得疲劳性能降低和疲劳寿命缩短。
The fatigue performance under typical corrosive environment is the prerequisite for fatigue life design of aeronautical metal structure. To this end, the experimental determination of smooth aluminum alloy 2E12-T3 and 7050-T7451 smooth specimens and notched specimens in a dry atmosphere and tank water environment Fatigue performance of SN curves, the phenomenon of observation, the fatigue performance comparison based on experimental data results, and the specimen fracture analysis by scanning electron microscopy (SEM) to study the corrosive environment of the fuel tank and the combined action of the load on the fatigue performance of the mechanism, the results show : The accumulator water environment adversely affects the fatigue performance of the material, and the fatigue load and the notch of the sample all aggravate the adverse effect of the corrosive environment on the fatigue performance of the material; the surface roughness caused by corrosion is more likely to cause fatigue cracking and cracking Electrochemical reactions and hydrogen embrittlement at the tip accelerate crack propagation, resulting in reduced fatigue performance and reduced fatigue life.