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(xiàn)衍射(XRD)、掃描電子顯微鏡(SEM)和X射線(xiàn)能譜(EDS)等對(duì)鍍層的結(jié)構(gòu)、微觀(guān)形貌及元素組成進(jìn)行分析.通過(guò)Tafel極化曲線(xiàn)、電化學(xué)阻抗譜(EIS)、開(kāi)路電位監(jiān)測(cè)及室內(nèi)加速腐蝕試驗(yàn),研究?jī)煞N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?xún)?yōu)于Ni-P鍍層.兩種鍍層的自腐蝕電位均負(fù)于銅.
關(guān)鍵詞:化學(xué)鍍;銅接地線(xiàn);弱酸性;土壤介質(zhì);耐蝕性
中圖分類(lèi)號(hào):O69 文獻(xiàn)標(biāo)識(shí)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(jì)的不斷發(fā)展,電力系統(tǒng)容量不斷增加,對(duì)接地裝置的性能提出了更高的要求.由于電網(wǎng)腐蝕帶來(lái)的電力事故逐漸增多,接地裝置的耐腐蝕性問(wèn)題日益受到人們的關(guān)注.日本、歐美等一些發(fā)達(dá)國(guó)家的接地線(xiàn)材料多采用銅金屬[ 1],而我國(guó)變電站多采用鍍鋅鋼材料,但是鍍鋅層對(duì)酸性土壤的耐蝕性較差,通常在南方酸性土壤介質(zhì)中運(yùn)行1~2年后,鍍鋅層就會(huì)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(hù)手段也很難使接地網(wǎng)在腐蝕性較強(qiáng)的土壤中得到長(zhǎng)期、有效的保護(hù).目前,根據(jù)國(guó)際接地材料的發(fā)展趨勢(shì),國(guó)內(nèi)部分地區(qū)已經(jīng)開(kāi)始采用銅或覆銅材料作為電網(wǎng)的接地材料.