电力金具表面电沉积Zn-Mn合金镀层及其耐蚀性能研究  

Electrodeposition of Zn-Mn alloy coating on the surface of power fittings and evaluation of its corrosion resistance

作　　者：李文峰 田江波 李佳 赵振华 Li Wenfeng;Tian Jiangbo;Li Jia;Zhao Zhenhua(Baoding Power Supply Branch,State Grid Hebei Electric Power Co.,Ltd.,Baoding 071000,China)

机构地区：[1]国网河北省电力有限公司保定供电分公司,河北保定071000

出　　处：《电镀与精饰》2024年第9期69-75,共7页Plating & Finishing

基　　金：国网河北省电力有限公司科技项目(kj2023-060)。

摘　　要：Zn镀层是一种常见的防腐涂层,可作为牺牲阳极为电力金具提供良好的阴极保护。电沉积制备的Zn合金镀层可进一步提高镀层的耐蚀性,为电力金具提供更为有效的防护。采用X射线衍射、扫描电子显微镜、动电位极化曲线和电化学阻抗谱分别对Zn-Mn合金镀层的物相、微观形貌和耐蚀性能进行了表征,研究了镀液中MnSO_(4)·H_(2)O的含量对Zn-Mn合金镀层的影响。结果表明,Zn-Mn合金镀层在3.5 wt.%NaCl溶液中具有明显的钝化特征,其腐蚀电流密度低于纯Zn镀层,电化学阻抗值大于纯Zn镀层。当镀液中的MnSO_(4)·H_(2)O的含量为33.8g/L时,所制备的Zn-Mn合金镀层(Zn-Mn Ⅱ)具有平整致密的表面形貌和较高的Mn含量,其耐蚀性能最好。Zn coating is one of the most commonly used anti-corrosion coating,which can act as a sacrificial anode to provide good cathodic protection for power fittings.The electrodeposited Zn alloy coatings can further improve the corrosion resistance,and provide more effective protection for electric fittings.To investigate the effects of MnSO4-H2O content in the plating bath on the Zn-Mn alloy coating,the X-ray diffraction(XRD),scanning electron microscopy(SEM),potentiodynamic polarization curve and electrochemical impedance spectroscopy(EIS)were employed to analyse the phase composition,micromorphology and corrosion resistance,respectively.The results show that the Zn-Mn alloy coating has obvious passivation characteristics in 3.5 wt.%NaCl solution.The corrosion current density of Zn-Mn alloy coating is lower than that of pure Zn coating,and the electrochemical impedance value of Zn-Mn alloy coating is bigger than that of pure Zn coating.When the MnSO_(4)·H_(2)O is 33.8 g/L,the optimized Zn-Mn alloy coating(Zn-Mn Ⅱ)exhibits a flat and dense surface topography and owns a high Mn content in the coating,resulting in the best corrosion resistance.

关 键 词：Zn-Mn合金镀层 电沉积 耐蚀性 钝化 电化学阻抗 

分 类 号：TG176[金属学及工艺—金属表面处理]