EFFECTS OF NEUTRON IRRADIATION ON LOW‐CYCLE FATIGUE AND TENSILE PROPERTIES OF AISI TYPE 304 STAINLESS STEEL AT 298 K

Abstract

Abstract— Room temperature studies have been made of the effect of neutron damage on the mechanisms concerned with the low‐cycle fatigue and tensile test behaviour of stainless steel AISI Type 304. Samples were irradiated in the HFR at Petten to a fast fluence of 5·1024 n m−2 (E > 0·1 MeV) at 333 K followed by mechanical testing at room temperature. The low temperature irradiation caused irradiation hardening: the 0·2 yield stress increased from 230 MN m−2 for the unirradiated material to a lower yield point value of 540 MN m−2. Irradiation had no significant effect on fatigue life. The loop type damage was removed by glide dislocations resulting in cyclic softening. Dislocation substructures were observed after fatigue testing: cell structures were more pronounced after fatigue testing to failure the higher the applied strain ranges. The formation of fatigue cracks at the surface of the specimens was observed in a series of specimens exposed to an increasing number of fatigue cycles. Copyright © 1979, Wiley Blackwell. All rights reserved