STP633: Effect of Stress on Radiation Damage in Neutron Irradiated Zirconium Alloys

    Northwood, DO
    Metallurgical engineer, technologist, and metallurgical engineerAssociate professor, Metallurgical Engineering Branch, Chalk River Nuclear LaboratoriesUniversity of Windsor, Chalk River, OntarioWindsor, Ontario,

    Gilbert, RW
    Metallurgical engineer, technologist, and metallurgical engineerAssociate professor, Metallurgical Engineering Branch, Chalk River Nuclear LaboratoriesUniversity of Windsor, Chalk River, OntarioWindsor, Ontario,

    Coleman, CE
    Metallurgical engineer, technologist, and metallurgical engineerAssociate professor, Metallurgical Engineering Branch, Chalk River Nuclear LaboratoriesUniversity of Windsor, Chalk River, OntarioWindsor, Ontario,

    Pages: 19    Published: Jan 1977


    Abstract

    Structures developed in zirconium alloys during irradiation creep have been characterized by transmission electron microscopy (TEM). Alloys investigated were annealed Zircaloy-2, cold-worked Zircaloy-2 and cold-worked Zr-2.5Nb pressure tube material. Thin films were taken from material deformed in the NRU, NRX and Pickering-3 reactors at temperatures of 530 to 600 K under stresses of 117 to 552 MPa giving strains in the range 0.14 to 8.8 percent. Stress-induced orientation of dislocation loops makes a negligible contribution to irradiation creep at all stresses. At the lower stresses (and hence strains), the size and distribution of the damage is unaffected by stress, being the same in the head and gage sections of creep specimens. At higher stresses (strains), there is much clearing of the damage by plastic deformation. The deformation however is very uneven, producing structures in different grains of the same specimen that can show no deformation, swaths cleared of irradiation damage, or dislocation tangles or cell formation. The relevance of these TEM observations to irradiation creep mechanisms is discussed.

    Keywords:

    zirconium, zirconium alloys, irradiation, radiation damage, electron microscopy, neutron irradiation, in-reactor creep


    Paper ID: STP35584S

    Committee/Subcommittee: B10.02

    DOI: 10.1520/STP35584S


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