Creep modelling for long-term low strain regime including the limit of negligible creep

    Research output: Contribution to conferenceConference articleScientificpeer-review

    Abstract

    The challenges in successfully predicting long term creep behaviour of common engineering materials, for example to design high temperature equipment for long term base load or cyclic spectrum service, include the need to consider the behaviour within a regime for which there is little support from testing data. The challenge is already present for established as-new parent materials and becomes even greater for new or ex-service materials, welding consumables and other situations with limited availability of relevant data. Numerous suggested approaches aim to overcome the challenge, for example by using various types of life fraction rules and parametric or comparable creep models for predicting long-term creep and creep rupture. The issue extends to the limit of negligible creep, or conditions where design for creep is no longer necessary. Unfortunately, there is no general agreement on how to model for creep and creep rupture within these long-term, low strain regimes and how to establish such limits. In this paper, we use the Wilshire model and available data on C-Mn, P22, 1CMV and P91 steels to evaluate a possible route for the purpose. The approach appears to show more consistent limits when these are set with strain-based rather than time-based rules.
    Original languageEnglish
    Number of pages6
    Publication statusPublished - 2017
    Event4th International Creep and Fracture Conference, ECCC 2017 - Düsseldorf, Germany
    Duration: 10 Sep 201714 Sep 2017

    Conference

    Conference4th International Creep and Fracture Conference, ECCC 2017
    Abbreviated titleECCC 2017
    CountryGermany
    CityDüsseldorf
    Period10/09/1714/09/17

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    Creep
    Welding
    Availability
    Steel
    Testing

    Keywords

    • creep
    • strain
    • negligible creep
    • design
    • long-term service
    • steel

    Cite this

    Auerkari, P., Holmström, S., Pohja, R., & Rantala, J. (2017). Creep modelling for long-term low strain regime including the limit of negligible creep. Paper presented at 4th International Creep and Fracture Conference, ECCC 2017, Düsseldorf, Germany.
    Auerkari, Pertti ; Holmström, Stefan ; Pohja, Rami ; Rantala, Juhani. / Creep modelling for long-term low strain regime including the limit of negligible creep. Paper presented at 4th International Creep and Fracture Conference, ECCC 2017, Düsseldorf, Germany.6 p.
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    title = "Creep modelling for long-term low strain regime including the limit of negligible creep",
    abstract = "The challenges in successfully predicting long term creep behaviour of common engineering materials, for example to design high temperature equipment for long term base load or cyclic spectrum service, include the need to consider the behaviour within a regime for which there is little support from testing data. The challenge is already present for established as-new parent materials and becomes even greater for new or ex-service materials, welding consumables and other situations with limited availability of relevant data. Numerous suggested approaches aim to overcome the challenge, for example by using various types of life fraction rules and parametric or comparable creep models for predicting long-term creep and creep rupture. The issue extends to the limit of negligible creep, or conditions where design for creep is no longer necessary. Unfortunately, there is no general agreement on how to model for creep and creep rupture within these long-term, low strain regimes and how to establish such limits. In this paper, we use the Wilshire model and available data on C-Mn, P22, 1CMV and P91 steels to evaluate a possible route for the purpose. The approach appears to show more consistent limits when these are set with strain-based rather than time-based rules.",
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    Auerkari, P, Holmström, S, Pohja, R & Rantala, J 2017, 'Creep modelling for long-term low strain regime including the limit of negligible creep', Paper presented at 4th International Creep and Fracture Conference, ECCC 2017, Düsseldorf, Germany, 10/09/17 - 14/09/17.

    Creep modelling for long-term low strain regime including the limit of negligible creep. / Auerkari, Pertti; Holmström, Stefan; Pohja, Rami; Rantala, Juhani.

    2017. Paper presented at 4th International Creep and Fracture Conference, ECCC 2017, Düsseldorf, Germany.

    Research output: Contribution to conferenceConference articleScientificpeer-review

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    T1 - Creep modelling for long-term low strain regime including the limit of negligible creep

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    AU - Holmström, Stefan

    AU - Pohja, Rami

    AU - Rantala, Juhani

    N1 - MIP: Safe and Sustainable

    PY - 2017

    Y1 - 2017

    N2 - The challenges in successfully predicting long term creep behaviour of common engineering materials, for example to design high temperature equipment for long term base load or cyclic spectrum service, include the need to consider the behaviour within a regime for which there is little support from testing data. The challenge is already present for established as-new parent materials and becomes even greater for new or ex-service materials, welding consumables and other situations with limited availability of relevant data. Numerous suggested approaches aim to overcome the challenge, for example by using various types of life fraction rules and parametric or comparable creep models for predicting long-term creep and creep rupture. The issue extends to the limit of negligible creep, or conditions where design for creep is no longer necessary. Unfortunately, there is no general agreement on how to model for creep and creep rupture within these long-term, low strain regimes and how to establish such limits. In this paper, we use the Wilshire model and available data on C-Mn, P22, 1CMV and P91 steels to evaluate a possible route for the purpose. The approach appears to show more consistent limits when these are set with strain-based rather than time-based rules.

    AB - The challenges in successfully predicting long term creep behaviour of common engineering materials, for example to design high temperature equipment for long term base load or cyclic spectrum service, include the need to consider the behaviour within a regime for which there is little support from testing data. The challenge is already present for established as-new parent materials and becomes even greater for new or ex-service materials, welding consumables and other situations with limited availability of relevant data. Numerous suggested approaches aim to overcome the challenge, for example by using various types of life fraction rules and parametric or comparable creep models for predicting long-term creep and creep rupture. The issue extends to the limit of negligible creep, or conditions where design for creep is no longer necessary. Unfortunately, there is no general agreement on how to model for creep and creep rupture within these long-term, low strain regimes and how to establish such limits. In this paper, we use the Wilshire model and available data on C-Mn, P22, 1CMV and P91 steels to evaluate a possible route for the purpose. The approach appears to show more consistent limits when these are set with strain-based rather than time-based rules.

    KW - creep

    KW - strain

    KW - negligible creep

    KW - design

    KW - long-term service

    KW - steel

    M3 - Conference article

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    Auerkari P, Holmström S, Pohja R, Rantala J. Creep modelling for long-term low strain regime including the limit of negligible creep. 2017. Paper presented at 4th International Creep and Fracture Conference, ECCC 2017, Düsseldorf, Germany.