China Electric Power Research Institute,Beijing 100192,China;
Institute of Engineering Technology,University of Science and Technology Beijing,Beijing 100083,China;
State Grid Corporation,Beijing 100031,China;
Faculty of Materials Metallurgy and Chemistry,Jiangxi University of Science and Technology,Ganzhou 341000,China;
Metal and Chemistry Research Institute,China Academy of Railway Sciences Corporation Limited,Beijing 100081,China;
ferritic steel; nanoparticles; interphase precipitation; thermal stability; ostwald ripening rate;