化學(xué)鍍非晶態(tài)Ni—P及Ni—Sn—P鍍層在弱酸性介質(zhì)中耐蝕性研究

周海暉++張承平++方晨旭++馮兵++徐松++廖作為++曠亞非

摘 要：以紫銅為基體，采用化學(xué)鍍制備了非晶態(tài)Ni-P，Ni-Sn-P鍍層.采用X射線衍射（XRD）、掃描電子顯微鏡（SEM）和X射線能譜（EDS）等對鍍層的結(jié)構(gòu)、微觀形貌及元素組成進行分析.通過Tafel極化曲線、電化學(xué)阻抗譜（EIS）、開路電位監(jiān)測及室內(nèi)加速腐蝕試驗，研究兩種鍍層在pH=5.5，wNaCl=3.5%，以及pH=5.5，wS=20%的土壤介質(zhì)中的耐蝕性能.結(jié)果表明，化學(xué)鍍非晶態(tài)Ni-P及Ni-Sn-P鍍層的自腐蝕電流密度是裸銅的4.5%和1.2%，兩種鍍層在酸性腐蝕介質(zhì)中具有比金屬銅更好的耐蝕性，并且化學(xué)鍍Ni-Sn-P鍍層耐蝕性優(yōu)于Ni-P鍍層.兩種鍍層的自腐蝕電位均負于銅.

關(guān)鍵詞：化學(xué)鍍；銅接地線；弱酸性；土壤介質(zhì)；耐蝕性

中圖分類號：O69 文獻標識碼：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

隨著經(jīng)濟的不斷發(fā)展，電力系統(tǒng)容量不斷增加，對接地裝置的性能提出了更高的要求.由于電網(wǎng)腐蝕帶來的電力事故逐漸增多，接地裝置的耐腐蝕性問題日益受到人們的關(guān)注.日本、歐美等一些發(fā)達國家的接地線材料多采用銅金屬[ 1]，而我國變電站多采用鍍鋅鋼材料，但是鍍鋅層對酸性土壤的耐蝕性較差，通常在南方酸性土壤介質(zhì)中運行1～2年后，鍍鋅層就會完全腐蝕[ 2].其它如：增大接地體截面、采用降阻劑、涂覆導(dǎo)電防腐涂料等保護手段也很難使接地網(wǎng)在腐蝕性較強的土壤中得到長期、有效的保護.目前，根據(jù)國際接地材料的發(fā)展趨勢，國內(nèi)部分地區(qū)已經(jīng)開始采用銅或覆銅材料作為電網(wǎng)的接地材料.