High temperature damage as an indicator of operating conditions and residual creep life

Pertti Auerkari, Jorma Salonen, Stefan Holmström, Anssi Laukkanen, L. Laaksonen, S. Mäkinen, V. Väänänen, R. Nikkarila

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

    Abstract

    Damage due to creep and associated mechanisms is typically life-limiting in the pressure retaining hot sections of power boilers, requiring inspections to support the condition and life assessment.
    Since a single local failure can result in a shutdown, it is important to find the critical hot spots that will determine the time to next failure, and to evaluate the condition at those spots.
    This paper aims to demonstrate the characteristic damage in terms of in-service condition and related clues for life assessment. In particular, the appearance of microstructural degradation, internal oxidation and intergranular creep cavitation can indicate the path and extent of deviations from the expected status in components.
    Examples are shown on ferritic boiler steels, with degradation and damage proceeding through somewhat comparable stages regardless of the material grade.
    Hence although there are large differences e.g. in the creep strength between alloys, the operating conditions should largely compensate for the differences in the mechanical properties, and the predicted life fraction is not a strong function of the material grade for the same level of in-service damage.
    However, uncompensated residual differences between materials also occur and are discussed with examples.
    Original languageEnglish
    Title of host publicationproceedings of the 12th International Conference on Creep and Fracture of Engineering Materials and Structures, JIMIS 11
    Place of PublicationSendai, Japan
    PublisherJapan Institute of Metals (JIM)
    Pages1-4
    ISBN (Print)978-488-90340-7-3
    Publication statusPublished - 2012
    MoE publication typeA4 Article in a conference publication
    Event12th International Conference on Creep and Fracture of Engineering Materials and Structures, JIMIS 11 - Kyoto, Japan
    Duration: 27 May 201231 May 2012

    Conference

    Conference12th International Conference on Creep and Fracture of Engineering Materials and Structures, JIMIS 11
    Abbreviated titleJIMIS 11
    CountryJapan
    CityKyoto
    Period27/05/1231/05/12

    Fingerprint

    Creep
    Boilers
    Internal oxidation
    Degradation
    Cavitation
    Temperature
    Inspection
    Mechanical properties
    Steel

    Cite this

    Auerkari, P., Salonen, J., Holmström, S., Laukkanen, A., Laaksonen, L., Mäkinen, S., ... Nikkarila, R. (2012). High temperature damage as an indicator of operating conditions and residual creep life. In proceedings of the 12th International Conference on Creep and Fracture of Engineering Materials and Structures, JIMIS 11 (pp. 1-4). Sendai, Japan: Japan Institute of Metals (JIM).
    Auerkari, Pertti ; Salonen, Jorma ; Holmström, Stefan ; Laukkanen, Anssi ; Laaksonen, L. ; Mäkinen, S. ; Väänänen, V. ; Nikkarila, R. / High temperature damage as an indicator of operating conditions and residual creep life. proceedings of the 12th International Conference on Creep and Fracture of Engineering Materials and Structures, JIMIS 11. Sendai, Japan : Japan Institute of Metals (JIM), 2012. pp. 1-4
    @inproceedings{93ec505e8692406e8aab4419ad82e7ef,
    title = "High temperature damage as an indicator of operating conditions and residual creep life",
    abstract = "Damage due to creep and associated mechanisms is typically life-limiting in the pressure retaining hot sections of power boilers, requiring inspections to support the condition and life assessment. Since a single local failure can result in a shutdown, it is important to find the critical hot spots that will determine the time to next failure, and to evaluate the condition at those spots. This paper aims to demonstrate the characteristic damage in terms of in-service condition and related clues for life assessment. In particular, the appearance of microstructural degradation, internal oxidation and intergranular creep cavitation can indicate the path and extent of deviations from the expected status in components. Examples are shown on ferritic boiler steels, with degradation and damage proceeding through somewhat comparable stages regardless of the material grade. Hence although there are large differences e.g. in the creep strength between alloys, the operating conditions should largely compensate for the differences in the mechanical properties, and the predicted life fraction is not a strong function of the material grade for the same level of in-service damage. However, uncompensated residual differences between materials also occur and are discussed with examples.",
    author = "Pertti Auerkari and Jorma Salonen and Stefan Holmstr{\"o}m and Anssi Laukkanen and L. Laaksonen and S. M{\"a}kinen and V. V{\"a}{\"a}n{\"a}nen and R. Nikkarila",
    year = "2012",
    language = "English",
    isbn = "978-488-90340-7-3",
    pages = "1--4",
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    Auerkari, P, Salonen, J, Holmström, S, Laukkanen, A, Laaksonen, L, Mäkinen, S, Väänänen, V & Nikkarila, R 2012, High temperature damage as an indicator of operating conditions and residual creep life. in proceedings of the 12th International Conference on Creep and Fracture of Engineering Materials and Structures, JIMIS 11. Japan Institute of Metals (JIM), Sendai, Japan, pp. 1-4, 12th International Conference on Creep and Fracture of Engineering Materials and Structures, JIMIS 11, Kyoto, Japan, 27/05/12.

    High temperature damage as an indicator of operating conditions and residual creep life. / Auerkari, Pertti; Salonen, Jorma; Holmström, Stefan; Laukkanen, Anssi; Laaksonen, L.; Mäkinen, S.; Väänänen, V.; Nikkarila, R.

    proceedings of the 12th International Conference on Creep and Fracture of Engineering Materials and Structures, JIMIS 11. Sendai, Japan : Japan Institute of Metals (JIM), 2012. p. 1-4.

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

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    T1 - High temperature damage as an indicator of operating conditions and residual creep life

    AU - Auerkari, Pertti

    AU - Salonen, Jorma

    AU - Holmström, Stefan

    AU - Laukkanen, Anssi

    AU - Laaksonen, L.

    AU - Mäkinen, S.

    AU - Väänänen, V.

    AU - Nikkarila, R.

    PY - 2012

    Y1 - 2012

    N2 - Damage due to creep and associated mechanisms is typically life-limiting in the pressure retaining hot sections of power boilers, requiring inspections to support the condition and life assessment. Since a single local failure can result in a shutdown, it is important to find the critical hot spots that will determine the time to next failure, and to evaluate the condition at those spots. This paper aims to demonstrate the characteristic damage in terms of in-service condition and related clues for life assessment. In particular, the appearance of microstructural degradation, internal oxidation and intergranular creep cavitation can indicate the path and extent of deviations from the expected status in components. Examples are shown on ferritic boiler steels, with degradation and damage proceeding through somewhat comparable stages regardless of the material grade. Hence although there are large differences e.g. in the creep strength between alloys, the operating conditions should largely compensate for the differences in the mechanical properties, and the predicted life fraction is not a strong function of the material grade for the same level of in-service damage. However, uncompensated residual differences between materials also occur and are discussed with examples.

    AB - Damage due to creep and associated mechanisms is typically life-limiting in the pressure retaining hot sections of power boilers, requiring inspections to support the condition and life assessment. Since a single local failure can result in a shutdown, it is important to find the critical hot spots that will determine the time to next failure, and to evaluate the condition at those spots. This paper aims to demonstrate the characteristic damage in terms of in-service condition and related clues for life assessment. In particular, the appearance of microstructural degradation, internal oxidation and intergranular creep cavitation can indicate the path and extent of deviations from the expected status in components. Examples are shown on ferritic boiler steels, with degradation and damage proceeding through somewhat comparable stages regardless of the material grade. Hence although there are large differences e.g. in the creep strength between alloys, the operating conditions should largely compensate for the differences in the mechanical properties, and the predicted life fraction is not a strong function of the material grade for the same level of in-service damage. However, uncompensated residual differences between materials also occur and are discussed with examples.

    M3 - Conference article in proceedings

    SN - 978-488-90340-7-3

    SP - 1

    EP - 4

    BT - proceedings of the 12th International Conference on Creep and Fracture of Engineering Materials and Structures, JIMIS 11

    PB - Japan Institute of Metals (JIM)

    CY - Sendai, Japan

    ER -

    Auerkari P, Salonen J, Holmström S, Laukkanen A, Laaksonen L, Mäkinen S et al. High temperature damage as an indicator of operating conditions and residual creep life. In proceedings of the 12th International Conference on Creep and Fracture of Engineering Materials and Structures, JIMIS 11. Sendai, Japan: Japan Institute of Metals (JIM). 2012. p. 1-4