IN-REACTOR LOW-CYCLE FATIGUE OF TYPE 0Kh16N15M3B STAINLESS STEEL

An investigation has been carried out on austenitic stainless steel 0Kh16N15M3B under normal conditions and also to neutron irradiation of 6.8 × 10¹⁶nm^-2s^-1 ( E > 0.1 MeV) intensity. Thin-walled torsion cylindrical specimens were tested in strain-controlled fully reversed loading mode at 923 K. Various ranges of strain, pre-loading fluences and half-cycle hold times (1, 5 and 30min) were applied. Neutron irradiation was found to result in hardening of the steel, stimulating cyclic stress relaxation and a reduction in cyclic life. When acting together, neutron irradiation and static loads cause a more significant reduction in the number of cycles to failure than if summed up as independent factors. Application of a kinetic failure criterion based on a damage parameter enables an estimation to be made of the limiting state of the steel under high-temperature cyclic loading with hold periods.