You are being redirected because this document is part of your ASTM Compass® subscription.
    This document is part of your ASTM Compass® subscription.


    Influence of the Initial Material Condition on the Deformation Behavior of Zircaloy Cladding Tubes in the High-α-Phase Region


      Format Pages Price  
    PDF (428K) 15 $25   ADD TO CART
    Complete Source PDF (18M) 843 $121   ADD TO CART

    Cite this document

    X Add email address send
      .RIS For RefWorks, EndNote, ProCite, Reference Manager, Zoteo, and many others.   .DOCX For Microsoft Word


    The influence of the initial material condition on the deformation behavior of Zircaloy cladding tubes at 600 and 800°C is systematically investigated by closed end creep rupture tests and transient burst tests in air. At 800°C the strain rate of the cladding tube diameter can be described by the Norton creep equation ˙ε = n exp(− Q/RT) with a constant structure parameter A, stress exponent n, and activity energy Q. The structure parameter A depends on the normalized initial stress σ0/G(T) (σ0 = initial stress; G(T) = temperature-dependent shear modulus) and the initial material condition of the cladding characterized by the yield stress at 400°C and the degree of cold work during the final rocking step.

    At 600°C nonstationary creep behavior is reported for the as-cold-worked and partly recrystallized material condition. The Norton creep equation can be maintained with the same constants n and Q if a time-dependent structure parameter is assumed. As a result, the structure parameter A(t) can be written as a function of (1) the “extended normalized annealing time” K(ϕ, t, T), which describes the influence of cold work ϕ, annealing time t, and temperature T on the degree of recrystallization, and (2) the creep deformation represented by the normalized true tangential stress σ(t)/G(T) of the cladding tube sample: A(t)AminAmaxA(t)=a[σ(t)G(T)K(ϕ,t,T)]b where Amin, Amax = empirical minimum and maximum values of A, respectively, and a, b = empirical constants, depending on the degree of cold work.

    The analytical treatment is extended to temperature transient processes by using in Eq 1 an effective temperature instead of the actual temperature. The empirical equation (1) together with the Norton creep equation enable the description of the strain rate history of a Zircaloy cladding tube in the temperature range between 600 and 800°C and the dependency on the initial material condition.


    Zircaloy-4, cladding tube, fuel rod, pressurized water reactor, deformation behavior, high temperature, creep rupture test, transient burst test, material condition, yield strength, degree of cold work, influence

    Author Information:

    Ortlieb, E
    Kraftwerk Union AG, Erlangen,

    Cheliotis, G
    Kraftwerk Union AG, Erlangen,

    Weidinger, HG
    Kraftwerk Union AG, Erlangen,

    Committee/Subcommittee: B10.05

    DOI: 10.1520/STP28142S