The team of the Institute of Nuclear Energy and Safety Technology of the Hefei Institute of Material Science of the Chinese Academy of Sciences has made new progress in the research of high temperature resistant structural materials resistant to liquid lead and bismuth corrosion: Research shows that the addition of Si element can improve the oxide dispersion and strengthen 9Cr steel (hereinafter referred to as 9Cr-ODS steel ) High temperature mechanical properties, and significantly improve its resistance to lead and bismuth corrosion.
As a lead-based reactor structural material, the corrosion performance of 9Cr-ODS steel in liquid lead-bismuth will directly affect the service performance of the reactor. In order to improve the corrosion resistance of 9Cr-ODS steel, the research and development team through technical research and experiments found that adding Si to the material can significantly improve the corrosion resistance of lead and bismuth. The results show that Si forms uniformly dispersed Y-Si-O nanoparticles in the matrix, with a number density of up to ~ 1024 m-3. At the same time, under the lead-bismuth corrosion environment, Si element is easy to form a Si-rich internal oxide layer, which can effectively block Oxygen in lead and bismuth diffuses to the matrix and the matrix elements dissolve in lead and bismuth, so that 9Cr-ODS steel has excellent high temperature performance and resistance to liquid lead and bismuth corrosion.
This research provides new ideas for the design of lead-bismuth corrosion-resistant materials, and is of great significance for the development of high-performance lead-based reactor structural materials.