【摘要】 通过周期浸润腐蚀试验研究了550 MPa级耐候桥梁钢在模拟工业大气环境下的腐蚀行为，结合扫描电子显微镜、X射线衍射和电子探针等测试方法对锈层微观形貌特征、腐蚀产物物相组成、锈层截面形貌以及元素分布规律进行了观察和分析，并讨论了高强耐候桥梁钢的耐大气腐蚀机理。结果表明：在模拟工业大气环境下，Q550qENH-A钢和Q550qENH-B钢的腐蚀失重率随腐蚀时间的延长呈现初期快速下降、后期趋于平稳的趋势，并且两种耐候钢的耐腐蚀性能均优于Q345B。Cr和Ni元素在两种耐候钢的锈层中发生富集，促进了α-FeOOH腐蚀产物的生成，提高了锈层结构的稳定性和致密性，锈层对腐蚀介质的阻碍作用得到增强，因此表现出优异的耐大气腐蚀性能。更多还原

【Abstract】 The corrosion behavior of 550 MPa weathering bridge steel in simulated industrial atmosphere was investigated by cyclic immersion corrosion tests. The microscopic morphology, phase composition of corrosion products, cross section morphology and element distribution of rust layer were observed and analyzed by means of scanning electron microscope, X-ray diffraction and electron probe. The mechanism of atmospheric corrosion resistance of high-strength weathering bridge steel was also discussed. The results indicated that the corrosion weight loss rate of Q550qENH-A steel and Q550qENH-B steel decreased rapidly at the initial stage and tended to be stable at the later stage with the extension of corrosion time in the simulated industrial atmosphere, and the corrosion resistance of the two kinds of weathering steels were better than that of Q345B. Cr and Ni were enriched in the rust layer of two kinds of weathering steels, which promoted the formation of α-FeOOH and improved the stability and compactness of the rust layer structure, thus the blocking effect of the rust layer on the corrosion medium was enhanced. Therefore, the weathering steels showed excellent atmospheric corrosion resistance.更多还原