Thermal creep of zircaloy-4 cladding under internal pressure.
- 1 January 1987
- journal article
- Published by Taylor & Francis in Journal of Nuclear Science and Technology
- Vol. 24 (2) , 111-119
- https://doi.org/10.3327/jnst.24.111
Abstract
Creep characteristics of Zircaloy-4 stress-releaved cladding under internal pressure were studied. Creep tests were conducted under 21 conditions chosen from the temperature range of 603∼693 K and the hoop stress of 49∼314 MPa. The maximum accumulated test period was 3,000 h. Diametral creep data were analyzed by separating the primary (transient) and the secondary (steady-state) creep, based on Darn's quasitheretical model, and the following equations were derived: Total creep strain: ε= εS P {1--exp(−-52( s t)0.5)}+ s t Saturated primary creep strain: εS P=2.16 × 10−2 ( s cal)0.109 Steady-state creep rate: s= 1.57 × 1013(E/T) {sinh(1.13 × 103σ/E)}2.1exp (−-2.72 × 105/RT). The apparent activation energy of the steady-state creep, which is 2.72 × 105 J/mol, is in good agreement with these of self-diffusion of Zr in Zr-Sn alloys and suggests the self-diffusion is the control mechanism.Keywords
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