from the conferences organized by TANGER Ltd.
Austenitic steel 316L with applied coating was studied to find a suitable material for impeller of main circulation pump at working conditions of small modular lead fast reactor. The chemical compatibility of the materials to the liquid metal environment was evaluated in liquid lead environment containing oxygen to ensure the oxidation while simulating temperature cycling. The operating temperature was controlled to vary between 450 °C and 520 °C, which are the temperatures that can occur in the system. The tests were designed to verify the effect of the different thermal expansion of the steel and the coatings on the corrosion resistance of the system. Austenitic steel 316L was used as a reference material and coatings base on Ti, Al, and W applied by physical vapor deposition were used for corrosion resistance improvement. Microscopical investigation identified oxidation, solution-based attack (SBA), and Pb penetration into the material. The damage to the coatings depended on their chemical composition and structure of the coating. However, in general, the application of the coating increased the resistance of the surface to corrosion damage and the thermal cycling did not affect the adhesion of the coating to the steel.
Keywords: Corrosion, coating, austenitic steel, impeller, heavy liquid metal© This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.