EMPIRICAL RELATIONS FOR TENSILE PROPERTIES OF AUSTENITIC STAINLESS-STEELS IRRADIATED IN MIXED-SPECTRUM REACTORS

An assessment has been made of available tensile property data relevant to the design of fusion reactors, especially near term devices expected to operate at lower temperatures than power reactors. Empirical relations have been developed for the tensile properties as a function of irradiation temperature for neutron exposures of 10-15, 20, 30, and 50 dpa. It was found that yield strength depends little on the particular austenitic alloy and little on the helium concentration. Strength depends upon initial condition of the alloy only for exposures of less than 30 dpa. Uniform elongation was found to be more sensitive to alloy and condition. It was also more sensitive than strength to helium level. However, below 500-degrees-C, helium only appeared to have an effect at 10-15 dpa. At higher temperatures, helium embrittlement was apparent, and its threshold temperature decreased with increasing neutron exposure level.