Oxide dispersion strengthened steels are candidate materials for structural constituents in IV generation fission nuclear reactors and for fusion nuclear reactors. A reduced activation nano-oxide strengthened ferritic steel is produced by mechanical alloying with an average grain size of 400 nm. The steel is produced starting from nanometric powders of Fe-14Cr-1W-0.4Ti mixed with 0.3% Y2O3 powders, grinded by a low-energy mechanical alloying for 300 h and additionally consolidated by hot extrusion. Different heat treatments are carried out in temperature range from 1050 °C and 1150 °C. Transmission electron microscopy (TEM) analysis of hot extruded sample shows a equiaxed ferritic microstructure (Fig. 1a) with a high dislocation density (Fig. 1b) and a massive precipitation of different oxides particles (Fig. 2a) and complex non stoichiometric nano-oxide particles Y-Ti-O lesser than 10 nm (Fig. 2b). The precipitates distribution exhibits a remarkable stability in temperature and reduces the loss of mechanical characteristics even after extended exposure at 800 °C. After the heat treatments at 1050-1150 °C, the microstructure evolves towards a bimodal grain distribution as showed in Fig. 3. An inhomogeneous distribution of oxide particles inside the grains and different particles sizes after the heat treatment are showed respectively in Fig. 4 (a-b) and Fig.5 (a-b).

Lovicu, G., Fava, A., Montanari, R., Pizzoferrato, R., Richetta, M., Varone, A., et al. (2017). ODS ferritic steel for nuclear reactors. LA METALLURGIA ITALIANA, 109(10), 59-67.

ODS ferritic steel for nuclear reactors

Fava A.;Pizzoferrato R.;Richetta M.;Varone A.;
2017-01-01

Abstract

Oxide dispersion strengthened steels are candidate materials for structural constituents in IV generation fission nuclear reactors and for fusion nuclear reactors. A reduced activation nano-oxide strengthened ferritic steel is produced by mechanical alloying with an average grain size of 400 nm. The steel is produced starting from nanometric powders of Fe-14Cr-1W-0.4Ti mixed with 0.3% Y2O3 powders, grinded by a low-energy mechanical alloying for 300 h and additionally consolidated by hot extrusion. Different heat treatments are carried out in temperature range from 1050 °C and 1150 °C. Transmission electron microscopy (TEM) analysis of hot extruded sample shows a equiaxed ferritic microstructure (Fig. 1a) with a high dislocation density (Fig. 1b) and a massive precipitation of different oxides particles (Fig. 2a) and complex non stoichiometric nano-oxide particles Y-Ti-O lesser than 10 nm (Fig. 2b). The precipitates distribution exhibits a remarkable stability in temperature and reduces the loss of mechanical characteristics even after extended exposure at 800 °C. After the heat treatments at 1050-1150 °C, the microstructure evolves towards a bimodal grain distribution as showed in Fig. 3. An inhomogeneous distribution of oxide particles inside the grains and different particles sizes after the heat treatment are showed respectively in Fig. 4 (a-b) and Fig.5 (a-b).
2017
Pubblicato
Rilevanza nazionale
Articolo
Esperti anonimi
Settore ING-IND/21 - METALLURGIA
Settore ING-IND/15 - DISEGNO E METODI DELL'INGEGNERIA INDUSTRIALE
Italian
Heat treatments; Low-energy mechanical alloying; Nanostructure, nano-oxides; Nuclear reactors; Ods steel
http://www.multimediasf.com/AIM/AIM_ottobre2017_web.pdf
Lovicu, G., Fava, A., Montanari, R., Pizzoferrato, R., Richetta, M., Varone, A., et al. (2017). ODS ferritic steel for nuclear reactors. LA METALLURGIA ITALIANA, 109(10), 59-67.
Lovicu, G; Fava, A; Montanari, R; Pizzoferrato, R; Richetta, M; Varone, A; Testani, C
Articolo su rivista
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2108/231033
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 2
  • ???jsp.display-item.citation.isi??? 2
social impact