THE EFFECTS OF LOW NEUTRON EXPOSURES AT LOW TEMPERATURES ON THE HARDNESS AND TENSILE PROPERTIES OF NATURAL URANIUM

Technical Report · Mon Jun 01 04:00:00 EDT 1959

OSTI ID:4221866

Bement, A L

Techniques for conducting low-exposure neutron irradiations of natural uranium at temperatures below 35 C are described. Tensile specimens were irradiated under these conditions to four exposure levels, the highest of which was 6.6 x 10/sup 17/ nvt. Hardness and tensile tests were conducted. A significant increase in Rockwell hardness occurred between 2.9 x 10/sup 15/ and 4.8 x 10/sup 16/ nvt. An exposure of 6.6 x 10/sup 17/ nvt effected a 90% increase in yield strength and a 60% decrease in unit elongation vtth respect to the unirradiated values. Irradiated specimens were annealed at 200, 300, and 400 C for 10 and 25 hr, following which hardness and tensile properties were measured to determine the extent of recovery. Essentially complete recovery occurred at 300 C for all exposures except 6.6 x 10/sup 17/ nvt which required a 400 C anneal to recover unirradiated property values. Hardening and recovery mechanisms are discussed. Microstress recovery observed by other investigators during irradiation at temperatures above 100 C was not observed. Assuming a vacancy diffusion process for recovery, the temperature at which vacancies become mobile in uranium is proposed to lie between 35 and 150 C. (auth)

• Research Organization: General Electric Co. Hanford Atomic Products Operation, Richland, Wash.
• DOE Contract Number: W-31-109-ENG-52
• NSA Number: NSA-13-019653
• OSTI ID: 4221866
• Report Number(s): HW-60326
• Country of Publication: United States
• Language: English

Related Subjects

ANNEALING
DEFECTS
DIFFUSION
HARDNESS
LOW TEMPERATURE
NATURAL URANIUM FUEL
NEUTRON FLUX
NEUTRONS
RADIATION DOSES
RADIATION EFFECTS
RADIATION EFFECTS ON MATERIALS
RECOVERY
TENSILE PROPERTIES
VACANCIES