Modeling and verification of creep strain and exhaustion in a welded steam mixer

Stefan Holmström (Corresponding Author), Juhani Rantala, Anssi Laukkanen, Kari Kolari, Heikki Keinänen, Olli Lehtinen

    Research output: Contribution to journalArticleScientificpeer-review

    3 Citations (Scopus)

    Abstract

    Structures operating in the creep regime will consume their creep life at a greater rate in locations where the stress state is aggravated by triaxiality constraints. Many structures, such as the welded steam mixer studied here, also have multiple material zones differing in microstructure and material properties. The three-dimensional structure as such, in addition to interacting material zones, is a great challenge for finite element analysis (FEA), even to accurately pinpoint the critical locations where damage will be found. The studied steam mixer, made of 10CrMo 9-10 steel (P22), has after 100,000 h of service developed severe creep damage in several saddle point positions adjacent to nozzle welds. FE-simulation of long term behavior of this structure has been performed taking developing triaxiality constraints, material zones, and primary to tertiary creep regimes into account. The creep strain rate formulation is based on the logistic creep strain prediction model implemented to ABAQUS , including primary, secondary, and tertiary creep. The results are presented using a filtering technique utilizing the formulation of rigid plastic deformation for describing and quantifying the developing “creep exhaustion.”
    Original languageEnglish
    Article number061405
    Number of pages6
    JournalJournal of Pressure Vessel Technology
    Volume131
    Issue number6
    DOIs
    Publication statusPublished - 2009
    MoE publication typeA1 Journal article-refereed

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    Keywords

    • ProperTune

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