Correlation between microstructural features and mechanical properties of irradiated LONGLIFE RPV steels

M. Serrano, F. Bergner, B. Radiguet, J. H. Lim, C. R. M. Grovenor, M. Hernandez-Mayoral, E. Meslin, K. Wilford, W. Van Renterghem, J. Kocik, S. Ortner, H. W. Viehrig, R. Chaouadi, M. Brumovsky, H. Hein, F. Gillemot, P. Todeschini, Tapio Planman, J. Ruoden, E. Altstadt

    Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientificpeer-review

    Abstract

    The possibility of extending the operational life of reactor pressure vessels (RPV) up to 80 years presents the problem of the availability of materials irradiated at high neutron fluence and low neutron flux. The ability of the existing trend curves to predict high fluence embrittlement is a question of debate, and a critical analysis of these curves should be based on a consistent microstructural examination of irradiated materials. Within the LONGLIFE 7FWP, neutron irradiated RPV materials, relevant for long term operation, some of them coming from surveillance programs, have been characterized by means of a combination of microstructural techniques (APT, SANS, TEM) and mechanical tests (hardness, tensile, impact and fracture toughness). In this paper the analysis of the links between microstructural features (solute nanoclusters, dislocation loops and voids) and hardening and embrittlement measurements by mechanical testing, is presented. Current hardening models, based on the contribution of precipitates, or nanoclusters, seem to underestimate irradiation hardening for very high fluences, mainly when matrix damage (dislocation loops) is observed. Regarding chemical composition effects, the predominant role of Ni and the synergism between Ni-Mn and Si are also identified. Low-Cu alloys show a threshold value of radiation induced features to produce an effect on mechanical properties which calls for further in-depth analyses.
    Original languageEnglish
    Title of host publicationProceedings of Fontevraud 8
    Publication statusPublished - 2014
    MoE publication typeA4 Article in a conference publication
    EventFontevraud 8: Conference on Contribution of Materials Investigations and Operating Experience to LWRs' Safety, Performance and Reliability - Avignon, France
    Duration: 15 Sep 201418 Sep 2014

    Conference

    ConferenceFontevraud 8
    CountryFrance
    CityAvignon
    Period15/09/1418/09/14

    Keywords

    • microstructure
    • reactor pressure vessel
    • steel

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  • Cite this

    Serrano, M., Bergner, F., Radiguet, B., Lim, J. H., Grovenor, C. R. M., Hernandez-Mayoral, M., Meslin, E., Wilford, K., Van Renterghem, W., Kocik, J., Ortner, S., Viehrig, H. W., Chaouadi, R., Brumovsky, M., Hein, H., Gillemot, F., Todeschini, P., Planman, T., Ruoden, J., & Altstadt, E. (2014). Correlation between microstructural features and mechanical properties of irradiated LONGLIFE RPV steels. In Proceedings of Fontevraud 8