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摘 要：以紫铜为基体，采用化学镀制备了非晶态Ni-P，Ni-Sn-P镀层.采用X射线衍射（XRD）、扫描电子显微镜（SEM）和X射线能谱（EDS）等对镀层的结构、微观形貌及元素组成进行分析.通过Tafel极化曲线、电化学阻抗谱（EIS）、开路电位监测及室内加速腐蚀试验，研究两种镀层在pH=5.5，wNaCl=3.5%，以及pH=5.5，wS=20%的土壤介质中的耐蚀性能.结果表明，化学镀非晶态Ni-P及Ni-Sn-P镀层的自腐蚀电流密度是裸铜的4.5%和1.2%，两种镀层在酸性腐蚀介质中具有比金属铜更好的耐蚀性，并且化学镀Ni-Sn-P镀层耐蚀性优于Ni-P镀层.两种镀层的自腐蚀电位均负于铜.

关键词：化学镀；铜接地线；弱酸性；土壤介质；耐蚀性

中图分类号：O69 文献标识码：A

Study of the Corrosion Resistance of Eletroless Amorphous

Ni-P and Ni-Sn-P Coatings in Weak Acidic Medium

ZHOU Hai-hui1， 2，ZHANG Cheng-ping1，2， FANG Chen-xu1，2， FENG Bing3，

XU Song3， LIAO Zuo-wei1，2， KUANG Ya-fei1，2

（1. State Key Laboratory of Chemo/Biosensing and Chemometrics ， Hunan Univ， Changsha， Hunan 410082， China；

2. College of Chemistry and Chemical Engineering， Hunan Univ， Changsha， Hunan 410082， China；

3. State Grid Hunan Electric Power Corporation Electric Power Research Institute， Changsha， Hunan 410007， China）

Abstract： Amorphous Ni-P and Ni-Sn-P coatings were prepared on pure copper substrates by electroless plating. The structure， surface morphology and composition of the as-plated coatings were characterized by X-ray diffraction （XRD）， scanning electron microscopy （SEM） and energy-dispersive analysis （EDS）. The corrosion resistance behaviors of the as-plated Ni-P and Ni-Sn-P coatings were investigated by Tafel polarization， electrochemical impedance spectroscopy （EIS）， open circuit potential and accelerating corrosion indoors in wNaCl=3.5% solution at pH 5.5 and in soil with a water content of wS=20% at pH 5.5. The results indicate that electroless amorphous Ni-P and Ni-Sn-p plating of the corrosion current density is 4.5% and 1.2% of the bare copper and the two coatings offer better corrosion resistance than copper in weak acidic corrosive medium， while Ni-Sn-P coating exhibits the best corrosion resistance. Besides， the two coatings have a negative shift of self-corrosion potential when compared with Cu substrate， showing a good application prospect as anodic protective coatings for Cu ground wires in acidic or weak acidic soil medium.

Key words： electroless plating； copper ground wire； weak acidity； soil medium； corrosion resistance

随着经济的不断发展，电力系统容量不断增加，对接地装置的性能提出了更高的要求.由于电网腐蚀带来的电力事故逐渐增多，接地装置的耐腐蚀性问题日益受到人们的关注.日本、欧美等一些发达国家的接地线材料多采用铜金属[ 1]，而我国变电站多采用镀锌钢材料，但是镀锌层对酸性土壤的耐蚀性较差，通常在南方酸性土壤介质中运行1～2年后，镀锌层就会完全腐蚀[ 2].其它如：增大接地体截面、采用降阻剂、涂覆导电防腐涂料等保护手段也很难使接地网在腐蚀性较强的土壤中得到长期、有效的保护.目前，根据国际接地材料的发展趋势，国内部分地区已经开始采用铜或覆铜材料作为电网的接地材料.