Quarterly progress report - metallurgy unit - April 1954--June 1954

Four irradiated tensile specimens were tested in the Radiometallurgy laboratory. The uranium was from a lot rolled at Simonds Saw and STeel Company, then beta heat treated by the triple dip process. The samples were irradiated to 310 MWD/AT. The corrected exposure was 620 MWD/T after compensating for the decrease in flux depression due to the specimen size. Two of the irradiated specimens were tested in the as-received condition while the other two were vacuum annealed at 400{degree}C for 15 hours prior to testing. When the tensile properties of the unirradiated controls, irradiated, and irradiated-annealed specimens were compared, it was observed that no marked change in modulus of elasticity occurred, the 0.1 percent offset yield strength increased by a factor of about two for the irradiated and irradiated-irradiated, and 35 for the irradiated-annealed specimens, compared to the controls. The marked change in mechanical properties on irradiation as well as the relatively small effect of the anneal, indicates that the foreign atom effect caused by fission product concentration and distribution is the controlling factor, and work-hardening type of damage is relatively insignificant