2010 年 51 巻 5 号 p. 1011-1015
Oxide dispersion-strengthened (ODS) ferritic steels have a good radiation resistance, high creep strength and a good swelling resistance. In such alloys, Zr is used to improve the creep properties by stabilizing the grains boundaries. The influence of the zirconium on the microstructure will be discussed is this study. The addition of Zr reduces strongly the number density of the inclusion distribution. The reduction factor is between 4 (transverse direction) to 15 (longitudinal direction). The addition of Zr reduces the formation of Al and Y oxides (micro scale). The carbide composition is also different according to the material composition. Zr-free material forms W/Ti carbides and Zr-added material forms Zr/Ti carbides without formation of W carbides (free enthalpy). Zr addition may be considered as very good in term of strength and corrosion resistance.
