Microstructural investigation of the stability under irradiation of oxide dispersion strengthened ferritic steels.

Isabelle Monnet (1) , P. Dubuisson (1) , Y. Serruys (1) , Marie-Odile Ruault (2) , O. Kaitasov (2) , Bernard Jouffrey (3)

1 SRMP - Service de recherches de métallurgie physique
2 CSNSM - Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse
3 MSSMat - Laboratoire de mécanique des sols, structures et matériaux

Some fuel pin cladding made from a ferritic steel reinforced by titanium and yttrium oxides were irradiated in the French experimental reactor Phenix. Microstructural examination of this alloy indicates that oxides undergo dissolution under irradiation. This irradiation shows the influence of dose and, in a smaller part, of temperature. In order to better understand the mechanisms of dissolution, three ferritic steels reinforced by Y2O3 or MgO were irradiated with different charged particles. Inelastic interactions induced by 1 MeV He ion irradiation do not lead to any modification, neither in their chemical composition, nor in their spatial and size distribution. In contrast, isolated Frenkel pairs created by electron irradiation lead to significant oxide dissolution with a radius decrease proportional to the dose. Moreover, the comparison between irradiation with ions (displacements cascades) and electrons (Frenkel pairs only) shows the importance of free point defects in the dissolution phenomena.

Domaines: Science des matériaux [cond-mat.mtrl-sci]; Physique Nucléaire Expérimentale [nucl-ex]

Isabelle Monnet, P. Dubuisson, Y. Serruys, Marie-Odile Ruault, O. Kaitasov, et al.. Microstructural investigation of the stability under irradiation of oxide dispersion strengthened ferritic steels.. Journal of Nuclear Materials, 2004, 335, pp.311-321. ⟨hal-00019076⟩