Effect of thermal aging on fracture mechanical properties and crack propagation behavior of alloy 52 narrow-gap dissimilar metal weld

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

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

    Abstract

    Determination of the fracture toughness properties and thermal aging behavior of dissimilar metal weld (DMW) joints is of utmost importance for successful structural integrity and lifetime analyses. This paper presents results from fracture resistance (J-R), fracture toughness (T0) and Charpy-V impact toughness tests as well as fractography performed for an industrially manufactured narrow-gap DMW mock-up (SA508-Alloy 52-AISI 316L). Tests were performed on post-weld heat treated, 5000 h aged and 10,000 h aged material. The results show that this DMW is tough at the SA 508-Alloy 52 interface, which typically is the weakest zone of a DMW. The DMW joint maintains its high fracture resistance also after thermal aging. Crack propagates for a large part in the carbon-depleted zone (CDZ) of SA 508 but deflects occasionally to the Alloy 52 side due to small weld defects in µm scale. Ductile-to-brittle transition temperature determined from Charpy-V impact toughness tests increases due to thermal aging, but only to a minor extent. No significant change is observed for the T0 transition temperature due to aging.

    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
    Pages733-747
    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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