在富集氯离子环境中钢丝绳吊索结构的腐蚀性能分析

Atmosphere Corrosion Analysis of Cable Wire in Chloride-rich Environment

氯离子是海洋大气中的重要成分,往往会腐蚀钢丝绳吊索。采用与西堠门大桥直径为60 mm的吊索类似结构的钢丝绳,利用室内加速试验模拟海洋大气中氯离子对钢丝绳吊索的腐蚀环境,研究了不同浓度氯离子环境下钢丝绳的腐蚀,并利用SEM(扫描电子显微镜)和XRD(X射线衍射)对腐蚀产物及形貌进行分析。结果表明:吊索结构钢丝绳在其它条件相同的情况下腐蚀速率随氯离子浓度的增加而增大,钢丝绳的腐蚀与其钢丝缠绕紧密程度密切相关,并且腐蚀产物积累分布不均匀,在钢丝缝隙处较多;吊索结构钢丝绳在条件相同的情况下腐蚀速率随时间的推移而减小;吊索结构钢丝绳与钢片腐蚀的微观物理结构有显著差异,即钢丝绳腐蚀无腐蚀裂缝而钢片腐蚀有腐蚀裂缝。

Wire rope sling tend to be corroded in marine atmosphere,as chloride is one of the most important factor.This study aims to explore the effect of certain structure on corrosion behavior,the structure of wire rope which is similar with sling of 60 mm diameter of Xihoumen bridge.Different concentration of chloride indoor accelerated test of the wire corrosion on cable was used to simulate marine atmospheric environment.The results of test were analyzed by SEM(Scanning Electron Microscope)and XRD(X-Ray Diffraction),to explain the mechanism.The results showed:the corrosion rate increased with the increase of chloride ion concentration,and corrosion behavior of wire rope was closely related with the tightness of wire coil,and the accumulation of corrosion products was not uniform,more products accumulated in the wire aperture;the corrosion rate of wire rope decreased with exposure time under the same condition;the difference of physical microstructure between wire rope and steel plate was obviously,in other words,the steel plate had the corrosion crack but wire rope didn’t have the corrosion crack.