The effect of coating with nano oxide on pitting corrosion of gas turbines blade

Abstract

The pitting corrosion of the gas turbines blade of the electrical power plant in south Baghdad was evaluated in this study. A number of corrosion samples with dimensions of (20 * 20 * 3mm) according to the standard (G70-30ASTM) were manufactured from blade metal which subjected to corrosion due to the long service of the turbine. First, the oxidizing layer was removed from the surface by grinding and polishing, then the electrolytic coating process was carried out by Nano oxides TiO2, Al2O3, ZrO2. After that the evaluation of pitting corrosion after the corrosion test using the potainsial state method and the application of the tafel equation to calculate the corrosion rate was done. The results showed that all nano oxides contributed to the improvement of the corrosion rate compared to the base metal and that the nano-zirconium oxide gave the highest improvement by 37% followed 24%by Nano aluminum oxide after that the titanium oxide17% compared with base metal.