4种涂层钢在变电站土壤中的腐蚀行为研究

Investigation of corrosion property of four kinds of coating in the transformer substation soil

采用高速电弧喷涂方法在Q235钢表面上分别制备纯Al涂层、Al Si合金涂层、Ni Al合金涂层、316L不锈钢涂层,通过对涂层钢在湖南某220 k V变电站中进行埋样和土壤溶液中的电化学实验,研究涂层在变电站土壤及其溶液中的耐蚀性能。通过电化学线性极化、动电位极化、交流阻抗试验,研究涂层在变电站土壤过滤液中的电化学腐蚀行为,并利用扫描电子显微镜和X射线电子能谱对埋样的腐蚀产物进行观察和分析,结果表明:Al Si涂层具有最好的耐土壤腐蚀性,其次是镍铝涂层和不锈钢涂层,而纯铝涂层长时间埋地容易鼓泡,耐土壤腐蚀性不佳。

Pure Al coating,Al Si alloy coating,Ni Al alloy coating and 316 L stainless steel coating were prepared on the Q235 steel by arc spraying technology. The corrosion of the four sprayed alloy coatings in the 220 k V transformer substation soil and soil solution was studied by buried specimens and electrochemical test in Hunan. The corrosion behaviors of the coating steel samples in transformer substation soil solution were investigated by line polarization, potentiodynamic polarization and electrochemical impedance spectroscopy( EIS) tests. The macrography and corrosion products were carried out scanning electron microscopy( SEM) and electron diffraction spectra( EDS). The results show that the best corrosion resistance of the four sprayed alloy coatings was Al Si coating,sequentially in the order of Ni Al and stainless steel coating,and the Al coating was easy bouffant in a long time in the underground,so that the corrosion resistance is not good.