桥梁缆索用高强锌铝合金镀层钢丝在中性盐雾环境中的腐蚀行为研究  

Corrosion Behavior in Neutral Salt Spray Environment of High Strength Zn-Al Alloy Coated Steel Wire for Bridge Cables

作　　者：陈思雨 王靖羽 高立强 CHEN Siyu;WANG Jingyu;GAO Liqiang(State Key Laboratory of Bridge Intelligent and Green Construction,China Railway Bridge Science Research Institute,Ltd.,Wuhan 430050,China)

机构地区：[1]中铁大桥科学研究院有限公司,桥梁智能与绿色建造全国重点实验室,武汉430050

出　　处：《中国腐蚀与防护学报》2025年第3期827-836,共10页Journal of Chinese Society For Corrosion and Protection

摘　　要：采用电化学测试和腐蚀失重方法,结合扫描电子显微镜(SEM)、X射线衍射仪(XRD)、超景深显微镜(SDM)等表面分析技术,研究了2100 MPa桥梁缆索锌铝合金镀层钢丝在中性盐雾环境中的腐蚀动力学规律及腐蚀机理。结果表明,锌铝合金镀层钢丝在中性盐雾环境中的腐蚀产物主要由Zn_(5)(OH)_(8)Cl_(2)·H_(2)O与Zn(OH)2组成,还有少量Al(OH)_(3)和Fe_(3)O_(4)生成。腐蚀行为可分为钝化膜溶解过程、富锌相溶解过程、富锌相和共晶相的过渡区间和锌铝共晶相的溶解过程4个阶段。在试验周期内,镀锌铝合金涂层体系极化电阻Rp先减小后增大,说明其耐蚀性先变弱后变强;钢丝腐蚀速率呈现先升高后降低的趋势,钢丝基体未出现明显点蚀坑、试样表面未出现其他腐蚀产物,腐蚀过程为全面腐蚀。采用回归分析腐蚀量-时间曲线,腐蚀速率增长随试验时间的延长而趋于缓慢,说明腐蚀产物对腐蚀具有延缓作用,锌铝合金镀层钢丝在中性盐雾环境中具有良好的耐蚀性。The corrosion kinetics and corrosion mechanism of Zn-Al alloy coated steel wire for 2100 MPa bridge cable in neutral salt spray environment were studied by means of electrochemical testing,corrosion loss measurement,scanning electron microscopy(SEM),X-ray diffractometer(XRD),ultra-depth of field microscopy(SDM)etc.The results show that the corrosion products of Zn-Al alloy coated steel wire are mainly composed of Zn(OH)_(2) and Zn_(5)(OH)_(8)Cl_(2)·H_(2)O,and a small amount of Al(OH)_(3) and Fe_(3)O_(4).The corrosion behavior can be divided into four stages:the dissolution process of passivated film,the dissolution process of zinc-rich phase,the dissolution process related with the transition interval of zinc-rich phase and eutectic phase,and the dissolution process of Zn-Al eutectic phase.During the test period,the polarization resistance Rp of the Zn-Al alloy coating decreases first and then increase,indicating that its corrosion resistance becomes weak first and then becomes strong.In other word,the corrosion rate of the steel wire increases first and then decreases.There is no obvious corrosion pits formed on the steel wire matrix and no red corrosion products on the surface of the sample.The regression analysis of the corrosion-time curve shows that the corrosion rate increases slowly with the extension of the test time,indicating that the corrosion products have a delaying effect on corrosion,therefore,the Zn-Al alloy coated steel wire has a good corrosion resistance in the neutral salt spray environment.

关 键 词：桥梁缆索钢丝 锌铝合金镀层 盐雾腐蚀性能 全面腐蚀 

分 类 号：TD123[矿业工程—矿山地质测量]