UNIAXIAL AND BIAXIAL CREEP-RUPTURE OF TYPE 316 STAINLESS STEEL AFTER FAST REACTOR IRRADIATION(a)

摘要

The results from both uniaxial and biaxial tests at 528 °C show significant losses in rupture life relative to unirradiated specimens when compared on the basis of initial true stress. Rupture life was reduced by factors down to 1/20 for uniaxial and by factors down to 1/40 for biaxial tests. The substantial loss in rupture life at 528 °C was primarily a result of high creep rates, and the contribution from ductility loss was relatively small. Uniaxial test results at 593 °C show reductions in rupture life of a factor of 1/5 at high stresses and only small reductions at low stresses. The rupture life for both uniaxial and biaxial tests at 649 °C show only a factor of 1/2 decrease after irradiation. The decrease becomes more substantial again at 760 °C with a factor of 1/10 to 1/7 reduction in life. The rupture life reductions at 5933 6493 and 760 °C were the results of reduced ductility 3 with no significant contributions from creep rate differences. The underlying cause of the low ductility at these higher temperatures is associated with helium embrittlement and defect structure.