Precipitate analysis of 9-12 % Cr ferritic/martensitic and ODS steels using the carbon replica technique

Full text of publication follows: 9-12 % Cr ferritic/martensitic steels were developed for the power industry and have been the choice alloys for specific nuclear environments. Advanced steels for use in high-neutron flux environments such as ADS, fusion walls, or spallation source windows are needed. Mechanical properties, especially those dependent upon radiation-damage induced microstructure change, are most important within these environments. Precipitate structure and distribution is based upon the alloy chemistries and heat treatments, and has influence on the mechanical properties. Precipitate structures of 17 ferritic/martensitic and four ODS steels with 9-12 % Cr including Eurofer-97, F82H, T91, HT-9, Eurofer-97 ODS, PM2000, etc., have been systematically studied using carbon replica TEM. Evaluations revealed morphological differences and distributions of such in grain matrixes or on the PAG/lathe boundaries. EDS analysis showed the chemical composition for suggested precipitate type. Size distributions of precipitates were produced along with the associated volume and number densities. These data were compared for differences of the steels. (authors)