Inhibiting hot corrosion of molten Li₂CO₃-Na₂CO₃-K₂CO₃ salt through graphitization of construction materials for concentrated solar power

Next-generation concentrated solar power (CSP) plants are expected to work above the current temperature limit of 565 °C for the benefit of enhanced efficiency. This poses significant challenges in the construction materials, among others, in terms of corrosion. In this work, we investigate the spray-graphitization method to improve the compatibility of SS310 and SS347 with molten Li₂CO₃-Na₂CO₃-K₂CO₃ carbonate salt. Improved compatibility was observed due to the formation of protective carbonate or carbide layers on SS347 and SS310 surfaces, respectively. Detailed characterization of the corrosion products, including chemical reactions and wettability allowed the mechanism of anticorrosion protection to be proposed, which could be used for other construction materials in direct contact with high-temperature molten salts for next-generation CSP plants and beyond.