The effect of thermomechanical processing on the creep behavior of Alloy 690

    Research output: Research - peer-reviewArticle

    • 4 Citations

    Abstract

    The effect of thermomechanical processing on the microstructure and elevated-temperature creep behavior of Alloy 690 was investigated. Commercially available sheet was subjected to four cycles of cold rolling to 25% deformation followed by annealing at 1000 °C for 1 h. Both the resultant microstructure and the original microstructure were characterized using electron backscattered diffraction. The thermomechanically processed microstructure exhibited a slightly lower fraction of twins and a smaller average grain size than the original microstructure. Tensile-creep experiments were performed in an open-air environment at temperatures between 650 and 690 °C and stresses between 75 and 172 MPa. The measured creep stress exponents (4-5) activation energies (320-368 kJ/mol) suggested that dislocation creep with lattice self-diffusion was dominant. The thermomechanically processed microstructure exhibited significantly worse creep resistance than the original as-processed microstructure. Thus, cyclic strain and annealing processing, which has been shown to improve the ductility-dip cracking susceptibility of Alloy 690, is not recommended for enhancing the creep resistance.

    LanguageEnglish (US)
    Pages233-237
    Number of pages5
    JournalMaterials Science and Engineering A
    Volume473
    Issue number1-2
    DOIs
    StatePublished - Jan 25 2008

    Profile

    Creep
    Microstructure
    Processing
    microstructure
    Creep resistance
    Annealing
    Temperature
    creep strength
    annealing
    temperature
    Cold rolling
    Electron diffraction
    Ductility
    Activation energy
    Experiments
    tensile creep
    cold rolling
    ductility
    electron diffraction
    grain size

    Keywords

    • Creep
    • Electron backscattered diffraction
    • Microstructure
    • Nickel-based alloy

    ASJC Scopus subject areas

    • Materials Science(all)

    Cite this

    The effect of thermomechanical processing on the creep behavior of Alloy 690. / Boehlert, C. J.

    In: Materials Science and Engineering A, Vol. 473, No. 1-2, 25.01.2008, p. 233-237.

    Research output: Research - peer-reviewArticle

    @article{370fb302507044d88458a37ed52e2b87,
    title = "The effect of thermomechanical processing on the creep behavior of Alloy 690",
    abstract = "The effect of thermomechanical processing on the microstructure and elevated-temperature creep behavior of Alloy 690 was investigated. Commercially available sheet was subjected to four cycles of cold rolling to 25% deformation followed by annealing at 1000 °C for 1 h. Both the resultant microstructure and the original microstructure were characterized using electron backscattered diffraction. The thermomechanically processed microstructure exhibited a slightly lower fraction of twins and a smaller average grain size than the original microstructure. Tensile-creep experiments were performed in an open-air environment at temperatures between 650 and 690 °C and stresses between 75 and 172 MPa. The measured creep stress exponents (4-5) activation energies (320-368 kJ/mol) suggested that dislocation creep with lattice self-diffusion was dominant. The thermomechanically processed microstructure exhibited significantly worse creep resistance than the original as-processed microstructure. Thus, cyclic strain and annealing processing, which has been shown to improve the ductility-dip cracking susceptibility of Alloy 690, is not recommended for enhancing the creep resistance.",
    keywords = "Creep, Electron backscattered diffraction, Microstructure, Nickel-based alloy",
    author = "Boehlert, {C. J.}",
    year = "2008",
    month = "1",
    doi = "10.1016/j.msea.2007.03.082",
    volume = "473",
    pages = "233--237",
    journal = "Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing",
    issn = "0921-5093",
    publisher = "Elsevier BV",
    number = "1-2",

    }

    TY - JOUR

    T1 - The effect of thermomechanical processing on the creep behavior of Alloy 690

    AU - Boehlert,C. J.

    PY - 2008/1/25

    Y1 - 2008/1/25

    N2 - The effect of thermomechanical processing on the microstructure and elevated-temperature creep behavior of Alloy 690 was investigated. Commercially available sheet was subjected to four cycles of cold rolling to 25% deformation followed by annealing at 1000 °C for 1 h. Both the resultant microstructure and the original microstructure were characterized using electron backscattered diffraction. The thermomechanically processed microstructure exhibited a slightly lower fraction of twins and a smaller average grain size than the original microstructure. Tensile-creep experiments were performed in an open-air environment at temperatures between 650 and 690 °C and stresses between 75 and 172 MPa. The measured creep stress exponents (4-5) activation energies (320-368 kJ/mol) suggested that dislocation creep with lattice self-diffusion was dominant. The thermomechanically processed microstructure exhibited significantly worse creep resistance than the original as-processed microstructure. Thus, cyclic strain and annealing processing, which has been shown to improve the ductility-dip cracking susceptibility of Alloy 690, is not recommended for enhancing the creep resistance.

    AB - The effect of thermomechanical processing on the microstructure and elevated-temperature creep behavior of Alloy 690 was investigated. Commercially available sheet was subjected to four cycles of cold rolling to 25% deformation followed by annealing at 1000 °C for 1 h. Both the resultant microstructure and the original microstructure were characterized using electron backscattered diffraction. The thermomechanically processed microstructure exhibited a slightly lower fraction of twins and a smaller average grain size than the original microstructure. Tensile-creep experiments were performed in an open-air environment at temperatures between 650 and 690 °C and stresses between 75 and 172 MPa. The measured creep stress exponents (4-5) activation energies (320-368 kJ/mol) suggested that dislocation creep with lattice self-diffusion was dominant. The thermomechanically processed microstructure exhibited significantly worse creep resistance than the original as-processed microstructure. Thus, cyclic strain and annealing processing, which has been shown to improve the ductility-dip cracking susceptibility of Alloy 690, is not recommended for enhancing the creep resistance.

    KW - Creep

    KW - Electron backscattered diffraction

    KW - Microstructure

    KW - Nickel-based alloy

    UR - http://www.scopus.com/inward/record.url?scp=37449026763&partnerID=8YFLogxK

    UR - http://www.scopus.com/inward/citedby.url?scp=37449026763&partnerID=8YFLogxK

    U2 - 10.1016/j.msea.2007.03.082

    DO - 10.1016/j.msea.2007.03.082

    M3 - Article

    VL - 473

    SP - 233

    EP - 237

    JO - Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing

    T2 - Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing

    JF - Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing

    SN - 0921-5093

    IS - 1-2

    ER -