document: The class of steels known as oxide dispersion strengthened (ODS) ferritic alloys (also known as nanostructured ferritic alloys) consist of a dispersion of ultra-fine oxide particles throughout the matrix. These oxide particles serve to improve the mechanical properties of the system, particularly at high temperatures, of the system through inhibiting dislocation motion and grain boundary sliding. In nuclear applications the oxide particles have been suggested to act as point defect sinks [10,11] to improve radiation tolerance, and as preferential sites for the formation of nano-scale He bubbles therefore reducing swelling compared to non-ODS steels [12–15]. The ability of the oxide particles to improve these properties depends on the structure and composition of the particles [10,11,16,17] and their stability under irradiation. Typical compositions of ODS steels include between 9 and 14at.% Cr for oxidation resistance (most commonly 14at.%); W for solid solution hardening; Y2O3 that is put into solid solution during the initial, mechanical alloying, process but then during consolidation at high temperatures forms precipitates; and Ti to inhibit significant growth of the oxide particles; the balance being made up of Fe and impurities [18]. For this reason these steels are often referred to as 14YWT, reflecting the constituent elements.
extractive_keyphrases: 14ywt balance class of steels consolidation constituent elements fe and impurities ferritic alloys improve radiation tolerance improve the mechanical properties of the system irradiation mechanical alloying nanostructured ods oxidation oxide dispersion strengthened oxide particles precipitates reducing swelling solid solution steels structure and composition of the particles ti w y2o3
abstractive_keyphrases: 9 and 14at.% cr dispersion of ultra-fine oxide particles throughout the matrix nano-scale he bubbles non-ods steels ods steels radiation swelling