Metallographic techniques for condition assessment and life prediction in SP249 guidelines

John Brear, Pertti Auerkari, Celso de Araujo

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

    Abstract

    The first phase of component assessment according to the SP249 Generic Guidelines comprises a code-based calculation of life consumption and a review of operating and maintenance history. Should the component prove unacceptable on any of the indicated criteria, then the Guidelines direct the assessor to move to a hands-on inspection, involving conventional NDE methods and various metallographic techniques. This paper outlines the latter approach. Microstructural degradation and corresponding thermal softening of the base metal can result in a variety of microstructural changes in the steel, such as changes in composition, structure, structure, size and spacing of carbides; in ferrite composition; in solid-solution strength; and in lattice parameter. Carbide characteristics, measured by direct observation or indirectly by hardness measurement, have proved the most sensitive indicator of thermal degradation. Creep damage (cavitation) can be measured directly. The two major applications of replication techniques are (1) the study of microstructure (creep cavitation, gain size, etc.) using surface replication and optical microscopy, and (2) the examination and identification of small second-phase particles by extraction replica techniques, as, for example, for the purpose of interparticle spacing determination.
    Original languageEnglish
    Title of host publicationApplication of knowledge bases systems technology in analysis and management of power and process plant components and systems
    Subtitle of host publicationSPRINT/KBS dissemination workshops of MPA Seminar
    EditorsAlexander S. Jovanovic
    Place of PublicationStuttgart
    PublisherMaterials Testing Institute University of Stuttgart MPA
    Pages2.3.1 - 2.3.29
    Volume3
    Publication statusPublished - 1994
    MoE publication typeA4 Article in a conference publication
    Event20. MPA Seminar - Stuttgart, Germany
    Duration: 6 Oct 19947 Oct 1994

    Seminar

    Seminar20. MPA Seminar
    CountryGermany
    CityStuttgart
    Period6/10/947/10/94

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  • Cite this

    Brear, J., Auerkari, P., & de Araujo, C. (1994). Metallographic techniques for condition assessment and life prediction in SP249 guidelines. In A. S. Jovanovic (Ed.), Application of knowledge bases systems technology in analysis and management of power and process plant components and systems: SPRINT/KBS dissemination workshops of MPA Seminar (Vol. 3, pp. 2.3.1 - 2.3.29). Materials Testing Institute University of Stuttgart MPA.