| Abstract: | The deformation behavior of Zircaloy-4 cladding was investigated under cyclic pressurization. A cyclic pressurization test for a cladding tube was carried out and a stress-life diagram of the cladding tube was constructed. The result showed that the O'Donnell and Langer relationship can be fitted to the fatigue behavior of the Zircaloy-4 cladding under cyclic pressurization with the frequency of 1 Hz by assuming the fatigue limit of 344.7 MPa at 350°C. In terms of the effect of a loading frequency, the stress-life diagram deviated from the O'Donnell and Langer relationship when the applied frequency decreased to 0.1 Hz. Based on the change of the diametral differences and fractographic observations, it was found that a combined creep-fatigue interaction rather than pure fatigue had an influence on the failure of the Zircaloy-4 cladding under cyclic pressurization at 350°C. |
