Application of noble cerium-based anti-corrosion sealing coating approach applied on electrical insulators installed in industrial regions

Abstract

Pin corrosion is a critical issue that causes premature rupture of high-voltage insulators. The development of efficient, defect-free, thermal resistive, hard, economical and environment-friendly sealing coating system is required to replace the current polymer-based highly toxic coatings for insulators. This study investigates the suitability of noble cerium (Ce)-based sealing coating film for use as an anti-corrosion coating for insulator pins installed in low-pH and highly corrosive sites. The coating bath parameters are optimized for the formation of a high-performance Ce-based protective sealing coating. After immersion in a 60 000 ppm CeCl ₃.7H ₂O sealing coating bath for 60 min, a Ce-rich and dense protective coating (24 µm) is formed on the pin surface. The life expectancy of the coated pin is 2.5 times higher than that of the non-coated galvanized pins. Electrochemical experiments and microstructural analysis demonstrate that Ce-based protective layers are suitable for long-term protection of high-voltage insulator pins in low-pH and high-corrosion-rate sites. We believe that this work would pave the way of developing ecofriendly anti-corrosion coatings for electric insulators and power industries.