Cyclic softening of tempered ferritic-martensitic steel P91

Jaromir Janousek, Stefan Holmström, Rami Pohja

    Research output: Contribution to conferenceConference articleScientific

    Abstract

    For the ferritic-martensitic steel P91 cyclic softening has been identified as important factor in the assessments of creep-fatigue in nuclear components. Better understanding of the cyclic softening is needed as it is believed to be the main contributor for the complex material behavior encountered in creep-fatigue testing. In fast reactor components the main life shortening load cycles are from thermal fluctuations causing through-wall stress gradients. The main objective of this work (as a Task in the European project MATISSE) is to perform tailored experiments and to develop models for understanding and predicting the cyclic-softening of P91. The supporting experimental program produces data for calibration and validations of the developed models. An existing elasto-viscoplasticity model simulates the key mechanisms such as decrease in dislocation density, increase in sub-grain size and recovering phenomena. The model will be modified to also incorporate the effect of hold time on the cyclic softening.
    Original languageEnglish
    Publication statusPublished - 2015
    Event31th Conference with International Participation on Computational Mechanics - Spicák, Czech Republic
    Duration: 9 Nov 201511 Nov 2015

    Conference

    Conference31th Conference with International Participation on Computational Mechanics
    CountryCzech Republic
    CitySpicák
    Period9/11/1511/11/15

    Fingerprint

    Martensitic steel
    Ferritic steel
    Creep testing
    Viscoplasticity
    Fatigue testing
    Fast reactors
    Creep
    Fatigue of materials
    Calibration
    Experiments

    Keywords

    • cyclic softening
    • creep-fatigue
    • P91 steel

    Cite this

    Janousek, J., Holmström, S., & Pohja, R. (2015). Cyclic softening of tempered ferritic-martensitic steel P91. Paper presented at 31th Conference with International Participation on Computational Mechanics, Spicák, Czech Republic.
    Janousek, Jaromir ; Holmström, Stefan ; Pohja, Rami. / Cyclic softening of tempered ferritic-martensitic steel P91. Paper presented at 31th Conference with International Participation on Computational Mechanics, Spicák, Czech Republic.
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    abstract = "For the ferritic-martensitic steel P91 cyclic softening has been identified as important factor in the assessments of creep-fatigue in nuclear components. Better understanding of the cyclic softening is needed as it is believed to be the main contributor for the complex material behavior encountered in creep-fatigue testing. In fast reactor components the main life shortening load cycles are from thermal fluctuations causing through-wall stress gradients. The main objective of this work (as a Task in the European project MATISSE) is to perform tailored experiments and to develop models for understanding and predicting the cyclic-softening of P91. The supporting experimental program produces data for calibration and validations of the developed models. An existing elasto-viscoplasticity model simulates the key mechanisms such as decrease in dislocation density, increase in sub-grain size and recovering phenomena. The model will be modified to also incorporate the effect of hold time on the cyclic softening.",
    keywords = "cyclic softening, creep-fatigue, P91 steel",
    author = "Jaromir Janousek and Stefan Holmstr{\"o}m and Rami Pohja",
    note = "LIS: Extended 2 page abstracts reviewed ; 31th Conference with International Participation on Computational Mechanics ; Conference date: 09-11-2015 Through 11-11-2015",
    year = "2015",
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    Janousek, J, Holmström, S & Pohja, R 2015, 'Cyclic softening of tempered ferritic-martensitic steel P91', Paper presented at 31th Conference with International Participation on Computational Mechanics, Spicák, Czech Republic, 9/11/15 - 11/11/15.

    Cyclic softening of tempered ferritic-martensitic steel P91. / Janousek, Jaromir; Holmström, Stefan; Pohja, Rami.

    2015. Paper presented at 31th Conference with International Participation on Computational Mechanics, Spicák, Czech Republic.

    Research output: Contribution to conferenceConference articleScientific

    TY - CONF

    T1 - Cyclic softening of tempered ferritic-martensitic steel P91

    AU - Janousek, Jaromir

    AU - Holmström, Stefan

    AU - Pohja, Rami

    N1 - LIS: Extended 2 page abstracts reviewed

    PY - 2015

    Y1 - 2015

    N2 - For the ferritic-martensitic steel P91 cyclic softening has been identified as important factor in the assessments of creep-fatigue in nuclear components. Better understanding of the cyclic softening is needed as it is believed to be the main contributor for the complex material behavior encountered in creep-fatigue testing. In fast reactor components the main life shortening load cycles are from thermal fluctuations causing through-wall stress gradients. The main objective of this work (as a Task in the European project MATISSE) is to perform tailored experiments and to develop models for understanding and predicting the cyclic-softening of P91. The supporting experimental program produces data for calibration and validations of the developed models. An existing elasto-viscoplasticity model simulates the key mechanisms such as decrease in dislocation density, increase in sub-grain size and recovering phenomena. The model will be modified to also incorporate the effect of hold time on the cyclic softening.

    AB - For the ferritic-martensitic steel P91 cyclic softening has been identified as important factor in the assessments of creep-fatigue in nuclear components. Better understanding of the cyclic softening is needed as it is believed to be the main contributor for the complex material behavior encountered in creep-fatigue testing. In fast reactor components the main life shortening load cycles are from thermal fluctuations causing through-wall stress gradients. The main objective of this work (as a Task in the European project MATISSE) is to perform tailored experiments and to develop models for understanding and predicting the cyclic-softening of P91. The supporting experimental program produces data for calibration and validations of the developed models. An existing elasto-viscoplasticity model simulates the key mechanisms such as decrease in dislocation density, increase in sub-grain size and recovering phenomena. The model will be modified to also incorporate the effect of hold time on the cyclic softening.

    KW - cyclic softening

    KW - creep-fatigue

    KW - P91 steel

    M3 - Conference article

    ER -

    Janousek J, Holmström S, Pohja R. Cyclic softening of tempered ferritic-martensitic steel P91. 2015. Paper presented at 31th Conference with International Participation on Computational Mechanics, Spicák, Czech Republic.