BETA-TO-ALPHA TRANSFORMATION CHARACTERISTICS OF SOME DILUTE URANIUM ALLOYS.

lattice strain was obtained after an air delay of only 2 seconds before quenching. Decreasing the annealing temperature results in a corresponding increase in the annealing time required for an equivalent amount of recrystallization. A second phase, present in the alloyed dingot metal, inhibited recrystallization and grain growth. Alloyed metal recrystallized progressively from the outer periphery to the center of the core, whereas unalloyed metal subjected to identical annealing conditions exhibited recrystallized grains throughout the cross section. A reduction in grain size from 0.38 mm to 0.25 mm occurred in a beta-treated, unalloyed core after annealing at 1200 deg F for 4 hours. The grain size of betaquenched, alloyed metal decreased from 0.28 mm to 0.19 mm on recrystallization. There appears to be change in the orientation of a beta-quenched core as a result of recrystallization. The beta quench-alpha anneal process could be integrated with an alpha-phase vacuum outgassing process to produce fine-grained metal that is essentially free of strain and preferred orientation and has a low hydrogen c ontent. (auth)