Evolution of microstructure and mechanical properties of 9Cr ferrite/martensite steels with different Si content after long-term aging at 550 °C

In view of developing novel alloys for applications in advanced Generation IV lead-cooled fast reactor (LFR) fuel cladding materials, four 9Cr ferrite/martensite (F/M) heat resistant steels with different Si content were developed. In the present work, the long-term thermal aging of 9Cr F/M steels was carried out in air at 550 °C for 500, 1000, 2000 and 5000 h. The microstructural evolution was investigated based on OM, SEM, EBSD and TEM...