Recent status and improvement of reduced-activation ferritic-martensitic steels for high-temperature service

L. Tan , Y. Katoh , A.-A.F. Tavassoli , J. Henry (1) , M. Rieth , H. Sakasegawa , H. Tanigawa , Q. S. Huang (2)

1 CEA-DES (ex-DEN) - CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire)
2 NIST - National Institute of Standards and Technology [Gaithersburg]

Reduced-activation ferritic-martensitic (RAFM) steels, candidate structural materials for fusion reactors, have achieved technological maturity after about three decades of research and development. The recent status of a few developmental aspects of current RAFM steels, such as aging resistance, plate thickness effects, fracture toughness, and fatigue, is updated in this paper, together with ongoing efforts to develop next-generation RAFM steels for superior high-temperature performance. In addition to thermomechanical treatments, including nonstandard heat treatment, alloy chemistry refinements and modifications have demonstrated some improvements in high-temperature performance. Castable nanostructured alloys (CNAs) were developed by significantly increasing the amount of nanoscale MX (M = V/Ta/Ti, X = C/N) precipitates and reducing coarse M23C6 (M = Cr). Preliminary results showed promising improvement in creep resistance and Charpy impact toughness. Limited low-dose neutron irradiation results for one of the CNAs and China low activation martensitic are presented and compared with data for F82H and Eurofer97 irradiated up to ∼70 displacements per atom at ∼300–325c.

Mots clés: reduced-activation ferritic-martensitic

Domaines: Physique Nucléaire Théorique [nucl-th]; Physique Nucléaire Expérimentale [nucl-ex]

L. Tan, Y. Katoh, A.-A.F. Tavassoli, J. Henry, M. Rieth, et al.. Recent status and improvement of reduced-activation ferritic-martensitic steels for high-temperature service. Journal of Nuclear Materials, 2016, 479, pp.515-523. ⟨10.1016/j.jnucmat.2016.07.054⟩. ⟨cea-02388601⟩