Evaluation of fracture behavior of recrystallized and aged high-Cr ODS ferritic steels

Effect of the heating rate on the microstructure of a ferritic ODS steel with four oxide formers (Y-Ti-Al-Zr) consolidated by spark plasma sintering (SPS)

“…The results of the small punch tests suggest small differences with the variation of the heating rate from room temperature to 500 °C, making the grain refinement insufficient to be detected by this method [61]. Independently of the heating rate used, all the materials processed are hardened by dislocation density and oxides precipitation.…”

Influence of the microstructure on the tensile and impact properties of a 14Cr ODS steel bar

“…Thus, the mechanical properties of ODS ferritic alloys might depend extensively on the fabrication path carried out and on the final microstructure obtained and its inhomogeneities [6][7][8][9]. Therefore, it will be important to study the ferritic grain size, the morphology of the grains, the presence of carbides and/or nitrides and the nanometric dispersion of complex oxides in the matrix, which seem to have high sink strength and trap both the fine He bubbles and vacancies mitigating the neutron irradiation damage [10][11][12].…”

ODS ferritic steels produced by an alternative route (STARS): microstructural characterisation after atomisation, HIPping and heat treatments

“…MA of powders to dissolve the Y 2 O 3 leads, after consolidation by HIP or hot extrusion, to an extremely fine submicrometric grain structure. 4,15–17 Oksiuta 18 obtained, after MA and HIPping at 1150°C during 2 hours, an ODS FS of composition Fe–14Cr–2W–0.3Ti–0.3Y 2 O 3 (wt-%) with a bimodal grain size distribution consisting of very small grains of about 250 nm and micrometric grains of up to 2 micrometres. The same behaviour was observed in Fe–13Cr–1W–0.3Ti–0.3Y 2 O 3 (wt-%) 19 and in Fe–13.5Cr–2W–(0.2–0.4)Ti–0.3Y 2 O 3 8 HIPped at 1150°C during 2–2.5 hours, where a bimodal grain size distribution was also observed, with extremely fine nanometric grains (200–500 nm) together with coarse grains of 1–8 micrometres.…”

“…10) thermodynamically more stable (ΔH f : −3874 KJ/mol) than the binary oxides TiO (ΔH f : −543 KJ/mol), TiO 2 (ΔH f : −944 KJ/mol) and Y 2 O 3 (ΔH f : −1907 KJ/mol). 17

10 BSE FEG-SEM images of samples HIPped at 900°C, HT at a 1220°C; and b 1300°C

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“…10) thermodynamically more stable (ΔH f : −3874 KJ/mol) than the binary oxides TiO (ΔH f : −543 KJ/ mol), TiO 2 (ΔH f : −944 KJ/mol) and Y 2 O 3 (ΔH f : −1907 KJ/mol). 17 After HIP at 900°C and HT at 1220°C, Y-and Ti-rich nanometric precipitates (Fig. 12a, green circle), probably TiC and Y 2 O 3 , and Y-, Ti-and Al-rich submicrometric precipitates (Fig.…”