Book Description

Reactor-grade Zircaloy-2 and vacuum-melted Zircaloy3V were prepared by arc melting twice under vacuum. In addition, argon-melted Zircaloy-3A was prepared by arc melting in a vacuum and then under Ar. The materials were rolled into plate. Specimens of the same thickness and having the same penultimate grain size were prepared at cold work levels of 10, 25, and 50%. The specimens were annealed at 300, 400, 500, 600, 700, and 800 un. Concent 85% C at He, and vacuum (10/sup -4/ to 10/sup -5/ mm Hg) atmospheres. Recovery, recrystallization, and grain growth as a function of cold work level, composition, annealing time, temperature, and atmosphere were studied by hardness and electric resistivity measurements, and by metallographic observations. Recovery and secondary hardening were observed at temperatures of 300 to 500 un. Concent 85% C. Recrystallization began at 500 un. Concent 85% C and was essentially complete at 600 un. Concent 85% C after 1000 min or less. Recrystallization occurred by subgrain growth in material cold worked 10%. Conventional nucleation and growth occurred at 25 and 50% cold work. Definite differences in response to annealing atmosphere were observed. Vacuum-annealed alloys recrystallized more slowly than air- or He-annealed alloys. (auth).