Effects of neutron irradiation on deformation behavior of nickel-base fastener alloys

Conference · Thu Jul 01 04:00:00 EDT 1999

OSTI ID:755393

Bajaj, R ^[1]; Mills, W J; Kammenzind, B F; Burke, M G

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1. Bettis Atomic Power Laboratory

This paper presents the effects of neutron irradiation on the fracture behavior and deformation microstructure of high-strength nickel-base alloy fastener materials, Alloy X-750 and Alloy 625. Alloy X-750 in the HTH condition, and Alloy 625 in the direct aged condition were irradiated to a fluence of 2.4x10{sup 20} n/cm{sup 2} at 264 C in the Advanced Test Reactor. Deformation structures at low strains were examined. It was previously shown that Alloy X-750 undergoes hardening, a significant degradation in ductility and an increase in intergranular fracture. In contrast, Alloy 625 had shown softening with a concomitant increase in ductility and transgranular failure after irradiation. The deformation microstructures of the two alloys were also different. Alloy X-750 deformed by a planar slip mechanism with fine microcracks forming at the intersections of slip bands with grain boundaries. Alloy 625 showed much more homogeneous deformation with fine, closely spaced slip bands and an absence of microcracks. The mechanism(s) of irradiation assisted stress corrosion cracking (IASCC) are discussed.

• Research Organization: Bettis Atomic Power Lab., West Mifflin, PA (US)
• Sponsoring Organization: US Department of Energy (US)
• DOE Contract Number: AC11-98PN38206
• OSTI ID: 755393
• Report Number(s): B-T-3242
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CRACK PROPAGATION
DEFORMATION
FRACTURE MECHANICS
FRACTURE PROPERTIES
INCONEL 625
MICROSTRUCTURE
NICKEL BASE ALLOYS
RADIATION EFFECTS
STRESS CORROSION
TEST REACTORS