STP1529: Texture Evolution of Zircaloy-2 During Beta-Quenching: Effect of Process Variables

    Romero, Javier
    School of Materials, The Univ. of Manchester, Manchester,

    Westinghouse Electric Sweden, Västeräs, SE

    Preuss, Michael
    School of Materials, The Univ. of Manchester, Manchester,

    Quinta da Fonseca, João
    School of Materials, The Univ. of Manchester, Manchester,

    Comstock, Robert J.
    Westinghouse Electric Company, Science and Technology Dept., Churchill, PA

    Dahlbäck, Mats
    Westinghouse Electric Sweden, Västeräs, SE

    Hallstadius, Lars
    Westinghouse Electric Sweden, Västeräs, SE

    Pages: 19    Published: Apr 2012


    Abstract

    The nuclear industry is interested in developing thermomechanical processes to produce random crystallographic orientation (texture) from cold-rolled Zircaloy-2 sheets used to manufacture boiling water reactor (BWR) channels. Randomized textures are beneficial because they minimize anisotropic irradiation-assisted growth, which in turn reduces bowing and uncontrolled deformation of BWR channels during service. The texture evolution of cold-rolled Zircaloy-2 sheets during the allotropic α→β→α phase trans formation was characterized by using synchrotron X-ray diffraction in situ and electron backscatter diffraction. The initial strong rolling texture is weakened only if the α→β→α phase transformation is complete. Plastic deformation and grain growth in the β-phase lead to changes in the β texture and modify the inherited α texture. The global texture evolution is not sensitive to levels of stress that do not cause β plastic deformation. These findings demonstrate that accurate temperature control of the β-quenching process is of utmost importance in order to minimize undesirable irradiation growth of BWR channels during service, and that plastic deformation in the β phase can be employed to modify the inherited α texture. BWR channels with β-quenched textures will exhibit minimum irradiation growth caused by texture.

    Keywords:

    Zircaloy-2, texture, beta-quenching, synchrotron X-ray diffraction, variant selection


    Paper ID: STP152920120008

    Committee/Subcommittee: B10.02

    DOI: 10.1520/STP152920120008


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