Microstructural characterization of alloy 52 narrow-gap dissimilar metal weld after aging

Teemu Sarikka, Roman Mouginot, Matias Ahonen, Sebastian Lindqvist, Ulla Ehrnstén, Pekka Nevasmaa, Hannu Hänninen

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

    1 Citation (Scopus)

    Abstract

    The safe-end dissimilar metal weld (DMW) joining the reactor pressure vessel to the main coolant piping is one of the most critical DMWs in a nuclear power plant (NPP). DMWs have varying microstructures at a short distance across the ferritic-austenitic fusion boundary (FB) region. This microstructural variation affects the mechanical properties and fracture behavior and may evolve as a result of thermal aging during long-term operation of an NPP. This paper presents microstructural characterization performed for as-manufactured and 5000 h and 10,000 h thermally aged narrow-gap DMW representing a safe-end DMW of a modern pressurized water reactor (PWR) NPP. The most significant result of the study is that the thermal aging leads to a significant decrease in a hardness gradient observed across the ferritic-austenitic FB of the as-manufactured DMW.

    Original languageEnglish
    Title of host publicationProceedings of the 18th International Conference on Environmental Degradation of Materials in Nuclear Power Systems – Water Reactors
    EditorsJohn H. Jackson, Denise Paraventi, Michael Wright
    PublisherSpringer
    Pages763-777
    Number of pages15
    Volume2
    ISBN (Electronic)978-3-319-68454-3
    ISBN (Print)978-3-319-68453-6
    DOIs
    Publication statusPublished - 1 Jan 2018
    MoE publication typeA4 Article in a conference publication
    Event18th International Conference on Environmental Degradation of Materials in Nuclear Power Systems - Water Reactors, 2017 - Portland, United States
    Duration: 13 Aug 201717 Aug 2017

    Publication series

    SeriesMinerals, Metals and Materials Series
    NumberPart F11
    ISSN2367-1181

    Conference

    Conference18th International Conference on Environmental Degradation of Materials in Nuclear Power Systems - Water Reactors, 2017
    Abbreviated titleEDM 2017
    CountryUnited States
    CityPortland
    Period13/08/1717/08/17

    Keywords

    • Aging
    • Dissimilar metal weld
    • Microstructural characterization
    • Ni-base alloy

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