Precipitate stability in Zircaloy-4: Final report

Technical Report · Fri Jan 01 00:00:00 EST 1988

OSTI ID:5490728

Yang, W J.S.

Zircaloy-4, a zirconium base alloy used extensively as cladding and core structural materials in water-cooled nuclear reactors, was examined by transmission electron microscopy after quench-and-aging treatments, neutron irradiation and postirradiation annealing. Phase instabilities found after quench-and-aging treatments include: (1) formation of the metastable precipitate Zr/sub 4/(Fe,Cr) during quench from the ..beta..-phase field and (2) dissolution of metastable Zr/sub 4/(Fe,Cr) and formation of the stable precipitate Zr(Fe,Cr)/sub 2/ during aging in the ..cap alpha..-phase field after quench. Rapid precipitation of Zr(Fe,Cr)/sub 2/ occurs on aging at 750/sup 0/C. Phase instabilities found after irradiation include amorphous transformation and dissolution of intermetallic Zr(Fe,Cr)/sub 2/ in the ..cap alpha..-recrystallized matrix and dissolution of the metastable precipitate Zr/sub 4/(Fe,Cr) in the ..beta..-quenched matrix. A complete solid solution is achieved in the irradiated, ..beta..-quenched matrix. Solute supersatuation in the matric is maintained to high fluences without new precipitation and segregation. Supersaturated Fe in the matric precipitates out at grain boundaries as the Zeta-phase during postirradiation annealing at 560/sup 0/C. Both Cr and Fe precipitate out as Zr(Fe,Cr)/sub 2/ intermetallics on annealing at 750/sup 0/C. In addition to the phase instabilities, irradiation also causes anti c dislocation development and grain growth by grain boundary migration.

• Research Organization: General Electric Co., San Jose, CA (USA)
• OSTI ID: 5490728
• Report Number(s): EPRI-NP-5591; ON: TI88920160
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
36 MATERIALS SCIENCE
BWR TYPE REACTORS
FUEL CANS
FUEL ELEMENTS
REACTOR MATERIALS
QUENCH AGING
RADIATION EFFECTS
ZIRCALOY 4
ANNEALING
CHROMIUM
DISLOCATIONS
DISSOLUTION
EXPERIMENTAL DATA
GRAIN GROWTH
GRAIN SIZE
HEAT TREATMENTS
IRON
IRRADIATION
MICROSTRUCTURE
NEUTRON FLUENCE
NICKEL
OXYGEN
PHASE TRANSFORMATIONS
PRECIPITATION
PROGRESS REPORT
QUENCHING
ZINC
AGING
ALLOYS
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
DATA
DOCUMENT TYPES
ELEMENTS
INFORMATION
LINE DEFECTS
MATERIALS
METALS
NONMETALS
NUMERICAL DATA
REACTOR COMPONENTS
REACTORS
SEPARATION PROCESSES
SIZE
TIN ALLOYS
TRANSITION ELEMENTS
WATER COOLED REACTORS
WATER MODERATED REACTORS
ZIRCALOY
ZIRCONIUM ALLOYS
ZIRCONIUM BASE ALLOYS
210100* - Power Reactors
Nonbreeding
Light-Water Moderated
Boiling Water Cooled
360106 - Metals & Alloys- Radiation Effects