ISSN: 1546-962X
Page Count: 16

Failure of Hydrided Zircaloy-4 Under Equal-Biaxial and Plane-Strain Tensile Deformation
Glendening, A
Penn State University, PA

Koss, DA
Penn State University, PA

Motta, AT
Argonne National Laboratory, IL

Pierron, ON

Daum, RS

Abstract

The fracture behavior of unirradiated Zircaloy-4 containing either solid hydride blisters or hydrided rims has been examined for the contrasting conditions of equal-biaxial and plane-strain tensile deformation at three temperatures (25°, 300°, and 375°C). Cold-worked and stress-relieved Zircaloy-4 sheet containing hydride blisters shows nearly identical failure strains in equal-biaxial and plane-strain tensile deformation for a wide range of blister or rim depths. In all cases, failure strains decrease rapidly with increasing hydride blister or rim thickness, especially in the ≤100 µm range. Test temperature has a significant effect on ductility with failure strains at 300° and 375°C being much greater than at room temperature. The results indicate that the ductility of material containing hydride rims/blisters greater than ≈ 30–40 µm deep is limited by crack growth, which occurs in a mode I manner at 25°C but in a mixed mode I/II manner at ≥300°C (and at higher failure strain levels).

Keywords:
Zircaloy-4, mechanical testing, hydride rim, hydride blisters, biaxial deformation, reactivity initiated accident

Paper ID: JAI12441
DOI: 10.1520/JAI12441
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