STP995V1: A Critical Assessment of Global Mechanical Approaches to Creep Crack Initiation and Creep Crack Growth in 316L Steel

    Bensussan, P
    Senior scientist, Etablissement Technique,

    Piques, R
    Graduate student and professor, Ecole,

    Pineau, A
    Graduate student and professor, Ecole,

    Pages: 28    Published: Jan 1988


    Abstract

    Both the initiation and propagation of macroscopic creep cracks have been studied in 316L stainless steel at 575 to 650C. This alloy was found to be creep ductile, which can be justified in terms of fracture mechanics concepts applied to creeping solids. Fracture mechanics is yet unable to provide unique correlations with global load-geometry parameters, such as K, J, or C*, for all the stages of both creep crack initiation and growth. Unique correlations nevertheless exist between C* and the time to initiation, and between C* and the Stage I to Stage II crack growth transition time. Time versus C* diagrams based on these latter correlations, in which creep crack initiation, slow creep crack growth, and fast creep crack growth regimes can be delimited, are the only global approach data which can be safely used for life prediction purposes in engineering applications.

    Keywords:

    Creep cracking, creep crack initiation, creep crack growth, fracture mechanics, viscoplasticity, viscoplastic fracture mechanics, finite-element analysis, creep damage, 316L stainless steel, nonlinear fracture mechanics


    Paper ID: STP26769S

    Committee/Subcommittee: E08.06

    DOI: 10.1520/STP26769S


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