Oñoro Salaices, MoisésMacías Delgado, JulioAuger, María A.Hoffmann, JanCastro Bernal, María Vanessa deLeguey Galán, Teresa2022-01-312022-01-312022-01Oñoro, M., Macías-Delgado, J., Auger, M. A., Hoffmann, J., de Castro, V. & Leguey, T. (2021). Powder Particle Size Effects on Microstructure and Mechanical Properties of Mechanically Alloyed ODS Ferritic Steels. Metals, 12(1), 69.2075-4701https://hdl.handle.net/10016/33995This article belongs to the Special Issue New Developments in Dispersion Strengthening of Metals and Alloys.Reduced activation ferritic (RAF) steels are expected to be widely used in challenging nuclear industrial applications under severe thermo-mechanical regimes and intense neutron loads. Therefore, actual research panorama is facing the strengthening strategies necessary to maximize both performance and endurance under these conditions. Oxide dispersion strengthened (ODS) RAF steels are leader candidates as structural materials in fusion energy reactors thanks to the reinforcement obtained with a fine dispersion of nanosized oxides in their matrix. In this study, the influence of the initial powder particle size and the selected processing route on the final material has been investigated. Two RAF ODS steels coming from atomized pre-alloyed powders with nominal particle powder sizes of 70 and 30 µm and composition Fe-14Cr-2W-0.4Ti-0.3Y2O3 (wt. %) were manufactured by mechanical alloying. Alloyed powders were compacted by hot isostatic pressing, hot crossed rolled, and annealed at 1273 K. Initial powder particle size differences minimize after milling. Both steels present an almost completely recrystallized material and similar grain sizes. The same type and distributions of secondary phases, Cr-W-rich, Ti-rich, and Y-Ti oxide nanoparticles, have been also characterized by transmission electron microscopy (TEM) in both alloy samples. The strengthening effect has been confirmed by tensile and Charpy impact tests. The two alloys present similar strength values with slightly better ductile brittle transition temperature (DBTT) and ductility for the steel produced with the smaller powder size.16eng© 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license.Atribución 3.0 EspañaODS steelPowder sizeFerritic steelMechanical alloyingEBSDNanoparticleOxideTEMresearch articleFísicahttps://doi.org/10.3390/met12010069open access69-1169-16Metals12AR/0000029028