2024-T3铝合金在模拟海洋大气环境中的腐蚀行为

Corrosion behavior of 2024-T3 aluminum alloy in simulated marine atmospheric environment

通过循环盐雾腐蚀实验,模拟2024-T3铝合金在海洋大气环境中的腐蚀过程。采用腐蚀质量损失测试、扫描电镜(SEM)、X射线能谱(EDS)和电化学技术分别对腐蚀117、242、362、487和598 h的2024-T3铝合金试样进行测试分析,得到腐蚀动力学、腐蚀产物和点蚀坑的形貌、腐蚀产物的成分以及表面锈层的电化学特性,研究锈层对2024-T3铝合金大气腐蚀的影响。动力学分析表明,腐蚀过程中2024-T3铝合金的表面形成了具有较好保护性的锈层;电化学测试结果表明,锈层的保护性呈现随腐蚀时间的延长先增强后减弱然后再略增强的变化过程。

The corrosion process of 2024-T3 aluminum alloy in marine atmospheric environment was simulated by a cycling salt spraying test. The corrosion evolution of 2024-T3 aluminum alloy as a function of corrosion time （117, 242, 362, 487, 598 h） was investigated by corrosion mass loss test, scanning electron microscopy （SEM）, energy-dispersive spectroscopy （EDS） and electrochemical techniques. Consequently, corrosion kinetics, the morphologies of corrosion products and pits, the composition of corrosion products and the electrochemical characters of rust layers were obtained. The influence of the rust layers on the atmospheric corrosion of 2024-T3 aluminum alloy was studied. The results of corrosion kinetics analysis show that the rust layers can well protect 2024-T3 aluminum alloy from corrosion. The results of electrochemical measurement further illustrate that the protective effect of the rust layers is first enhanced, and then weakened, at last enhanced slightly again as the corrosion time increases.