Effects of texture and temperature cycling on irradiation growth in cold-worked Zircaloy-2 at 353°K and 553°K

摘要

Irradiation growth and temperature cycling experiments have been performed at 353 exp 0 K and 553 exp 0 K on specimens taken from both longitudinal and transverse directions of 25% cold worked Zicaloy-2 pressure tube. For the longitudinal and transverse directions of 25% cold worked Zircaloy-2 pressure tube. For the longitudinal data, significant positive strains occur below a dose of 10 exp 24 n/m exp 2 at both temperatures, the larger strains occurring at the lower temperature. Above this dose, longitudinal growth strains increase almost linearly with irradiation. The linear rate is greater at 553 exp 0 k than 353 exp 0 K. In transverse specimens a small positive transient strain occurs below a dose of 10 exp 24 n/m exp 2 and negative growth rates are observed above this dose. It is suggested that the transient low dose growth behaviour at 353 exp 0 K and 553 exp 0 K and 553 exp 0 K contains a substantial fraction of volume increase. The effects of changes in irradiation temperature on growth strains in cold-worked Zircaloy-2 have been studied. Lowering irradiation temperature produces an initial positive transient strain which is almost fully recovered on raising the temperature again. Growth data obtained on longitudinal specimens cycled between 353 exp 0 K and 553 exp 0 K during irradiation lends strong support to a model of growth for cold-worked Zircaloy-2 consisting of a transient recoverable growth component due to interstitial clustering of prism planes and a non-recoverable linear component due to interstitial induced dislocation climb. (Atomindex citation 10:494161)