Microstructural explanation for irradiation embrittlement of V-15Cr-5Ti

Conference · Tue Oct 31 23:00:00 EST 1989

DOI:https://doi.org/10.1016/0022-3115(91)90355-B· OSTI ID:5281096

Gelles, D. S.; Ohnuki, S.; Loomis, B. A.; Takahashi, H.; Garner, F. A. ^[1]

---

1. Pacific Northwest Lab., Richland, WA (USA)

Vanadium alloys are candidate materials for first wall fusion reactor applications based on low induced activity and heat resistant response. However, recent results have indicated that modest levels of neutron irradiation damage in V-15Cr-5Ti lead to severe degradation of mechanical properties. In order to explain the observed behavior, specimens of V-15Cr-5Ti have been examined by transmission electron microscopy following irradiation at 600{degree}C to 14 dpa in the Fast Flux Test Facility (FFTF). The conditions examined included two heats of V-15Cr-5Ti with very different oxygen contents and, in one case, a section of a charpy specimen demonstrated to have very poor impact resistance. Specimens irradiated at 420 and 520{degree}C were also examined to confirm density change measurements that indicated swelling levels as high as 2.5%. Following irradiation at 600{degree}C, a complex microstructure was found that included a perfect dislocation network of line segments and loops, faulted loops, a high density of black spot damage and a high density of rod-shaped precipitates. Heat-to-heat variations did not appear to significantly alter these microstructural features; instead the density of large blocky precipitates, believed to be TiO{sub 2}, was found to have increased with increasing oxygen content. Only two of the specimens irradiated at 600{degree}C contained voids, whereas none of the specimens irradiated at 420 or 520{degree}C contained voids. 13 refs., 8 figs., 2 tabs.

• Research Organization: Pacific Northwest Lab., Richland, WA (USA)
• Sponsoring Organization: DOE/ER
• DOE Contract Number: AC06-76RL01830
• OSTI ID: 5281096
• Report Number(s): PNL-SA-17021; CONF-891204--8; ON: DE90004112
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360103 -- Metals & Alloys-- Mechanical Properties
360106 -- Metals & Alloys-- Radiation Effects
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700209* -- Fusion Power Plant Technology-- Component Development & Materials Testing
ALLOYS
CHROMIUM ALLOYS
CRYSTAL STRUCTURE
EMBRITTLEMENT
IRRADIATION
MATERIALS
MECHANICAL PROPERTIES
MICROSTRUCTURE
PHYSICAL RADIATION EFFECTS
RADIATION EFFECTS
SWELLING
THERMONUCLEAR REACTOR MATERIALS
TITANIUM ALLOYS
VANADIUM ALLOYS
VANADIUM BASE ALLOYS
VOIDS