Ceramic Coating for High Temperature Corrosion Protection of Steel

Abstract

In high temperature environments where oxidation occurs which effects the metal in multiple ways. High temperature corrosion is typically seen in ductile steel. This can cause abrupt failure and reduce a metal's mechanical properties. A variety of ceramic coatings are available that can be applied to enhance functionality and prevent corrosion, particularly at high temperatures. The majority of ceramic coatings are typically electrically nonconducting, making them excellent insulators. It also has a high melting temperature of up to 4000⸰F and remarkable abrasion resistance. Due to these characteristics, they offer exceptional corrosion resistance and strong abrasion resistance in high temperature conditions. In this research, the team synthesize ceramic coating which may provide exceptional abrasion resistant as well high temperature oxidation resistance. Before selecting the ingredients, it needs to be examined the compatibility between mild steel (sample) and constituents of ceramic coating, majorly the thermal expansion characteristics. It must be identical otherwise fractures can be produced on the coated surface of a metal. Samples were made as per demand, following collecting a sample and cleaned accurately to attach the coating appropriately. After application of coating on sample it should place in furnace which promote diffusion on a metal surface and construct protective barrier. Further, dipping the sample in 3.5% NaCl solution for 21 days and execute the OCP and EIS test of naked sample and coated sample correspondingly for 5 days. Potentiostat provides several graphs viz OCP, Bode plot, Nyquist impedance plot and Tafel Extrapolation. High temperature oxidation resistance of the ceramic covering was investigated using TGA analysis. The weight gain of coated sample is roughly 1mg/cm2 compared to about 4 mg/cm2 for plain sample in TGA curve. This illustrates that the ceramic coating is averting oxidation of steel surface at high temperature of 500ºC.