The effects of temperature and dose-rate variations on the creep of austenitic stainless steels in the dounreay fast reactor

Loaded helices of cold-worked, austenitic stainless steels (En58B, E, J, FV548 and type 316) have been irradiated in DFR at damage rates ranging over an order of magnitude at temperatures between 513 and 633 K. Creep rates varied between steels but a common pattern emerged where strain per unit dose appeared to increase with decreasing dose-rate. Comparison with experiments at 773 K on three of the steels reveals creep rate increases by factors ranging from 1.2 to 5. The results are discussed in the context of other fast reactor data and possible explanations of the findings are considered. (orig.)