中文摘要：

研究了轨道交通用铝合金防护涂层（磷化底漆＋纳米复合环氧底漆＋纳米复合聚氨酯面漆）在典型高温高湿地区（广州）的自然环境腐蚀老化行为。腐蚀老化1 a后,涂层表面出现孔洞,涂层色差值随老化时间的延长逐渐升高。衰减全反射傅立叶变换红外光谱（ATR-FTIR）的分析表明,聚氨酯树脂出现降解。涂层的电化学阻抗谱分析表明,虽然涂层树脂出现降解,涂层仍然保持优异的耐腐蚀能力。

英文摘要：

The degradation of a typical organic coating system composited of phosphide priming paint, nano-composite epoxy primer and nano-composite polyurethane topcoat for protection of AI-alloy used for transportation was investigated by out-door exposure test for 1 a in Guangzhou, a region of high- temperature and high-humidity in the Southern China. After 1 a exposure, some corrosion related spots were found on the coating surface. The color difference of the coating increases with the time. The analy- sis of attenuated total reflectance Fourier transform infrared spectroscopy indicates that the degradation of polyurethane resin occurred on the coating. The analysis of electrochemistry impedance spectra shows that the coating keeps high corrosion protectiveness as it was although degradation of polyure-thane resin took place.