Tritium Decay, Irradiation and Hydrogen/Helium Effects on Type 316L Austenitic Stainless Steel
The deleterious effects of hydrogen on the mechanical properties of austenitic stainless steels are frequently magnified by the presence of helium. Helium can be introduced into steel by either tritium absorption, diffusion and decay (tritium-tricked) or by implantation during irradiation. Displacement damage, which accompanies irradiation-induced hydrogen/helium implantation, is not associated with tritium, deuterium and/or protium absorption and tritium decay. Therefore, the microstructure of irradiated steel containing any given level of transmutation induced hydrogen and/or helium will differ significantly from the microstructure of a tritium tricked steel because of the interactions of hydrogen and helium with the irradiation induced defect structure. The defect structures (black spot damage, bubbles and/or faulted Frank loops) developed during low temperature (T less than 200 degrees C) irradiation trap the implanted hydrogen and helium. The trapping reduces atom mobility and hen ce the ability of the hydrogen and helium to either agglomerate (form bubbles) or accumulate at potential crack sites. The absence of such trapping in tritium-tricked steel causes the response to thermal/mechanical parameters to differ considerably from the response of irradiated steel containing similar hydrogen and helium concentrations. This difference in response minimizes the effects of hydrogen and helium on the low temperature mechanical properties of irradiated steels. Additionally, this difference causes irradiated steel to be less weldable than a tritium-tricked steel containing the same amount of helium.
- Research Organization:
- Savannah River Site (SRS), Aiken, SC (United States)
- Sponsoring Organization:
- US Department of Energy (US)
- DOE Contract Number:
- AC09-96SR18500
- OSTI ID:
- 799737
- Report Number(s):
- WSRC-MS-2001-00040; TRN: US200224%%694
- Resource Relation:
- Conference: Hydrogen Effects on Material Behavior, Moran, WY (US), 09/22/2002--09/27/2002; Other Information: PBD: 30 Apr 2002
- Country of Publication:
- United States
- Language:
- English
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