RECOVERY AND RECRYSTALLIZATION OF ZIRCONIUM AND ITS ALLOYS. PART 2. ANNEALING OF COLD-WORKED ZIRCONIUM
Hardness, x-ray diffraction, electrical resistivity, and metallography were used to study the annealing of coldworked zirconium at temperatures from 300 to 800 deg C (570 to 1470 deg F). Cold work, annealing time, temperature, and furnace atmosphere were chosen as variables. Recrystallization of 25 and 50 per cent cold-worked zirconium occurred by nucleation and growth of new grains and was complete after 10 minutes at 650 deg C (1200 deg F) and 620 deg C (ll65 deg F); l00 minutes at 620 deg C (1148 deg F) and 600 deg C (1110 deg F); 1000 minutes at 590 deg C (1095 deg F) and 550 deg C (1020 deg F, respectively. Recrystallization of 10 per cent cold-worked zirconium seemed to proceed by the growth of existing grains within a partially annealed matrix. After 10, 100, and 1000 mln anneals recrystallizatlon was complete at 670 deg C (1240 deg F), 650 deg C (1200 deg F), and 610 deg C (1130 deg F). For 10, 25, and 50 per cent cold- worked zirconium, the asrecrystallized grain size was 0.045, 0.026, and 0.016 mm, respectively. Grain growth following recrystallization was negligible. The highest value of n in the equation D = kt/sup n, where D is the grain diameter, n and k are constants, and t the time of anneal, was 0.07, describing growth during annealing of 50 per cent cold-worked zirconium. Secondary recrystallization occurred after vacuum anneals at 800 deg C (1470 deg F) for long periods of time. Anneals in air or commercial ungettered helium had no effect on recovery, recrystallization, or grain growth kinetics, but did inhibit secondary recrystallization. Impurities were picked up during the air and helium anneals and to a much smaller extent during elevated temperature anneals in vacuum (10/sup -4/ to 10/sup -5/mm mercury). (auth)
- Research Organization:
- General Electric Co. Hanford Atomic Products Operation, Richland, Wash.
- DOE Contract Number:
- AT(45-1)-1350
- NSA Number:
- NSA-16-003422
- OSTI ID:
- 4828276
- Report Number(s):
- HW-69679
- Country of Publication:
- United States
- Language:
- English
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