Deformation and fracture characteristics of Inconel X-750 at room temperature and elevated temperatures
Electron fractographic and thin foil electron metallographic techniques were used to evaluate the deformation and fracture characteristics of Inconel X-750 at temperatures ranging from 24 to 816/sup 0/C. Operative dislocation mechanisms and fracture surface morphologies were related to the overall tensile response of this nickel-base superalloy. At room temperature, failure occurred primarily by an intergranular dimple rupture mechanism associated with microvoid coalescence along grain boundary denuded regions. A fairly high density of dislocations throughout the matrix resulted in relatively high ductility levels even though failure occurred by an intergranular mechanism. Under intermediate temperature conditions (316 to 427/sup 0/C), increased transgranular fracture coupled with extensive dislocation activity within the Inconel X-750 matrix caused a slight increase in ductility. At progressively higher temperatures, 538 to 704/sup 0/C, all dislocation activity was channeled through narrow slip bands which subsequently initiated localized separation and resulted in a very faceted fracture surface appearance. The absence of a homogeneous dislocation substructure in this temperature regime resulted in a severe degradation in ductility levels. At the highest test temperature (816/sup 0/C), a uniform dislocation network throughout the Inconel X-750 matrix coupled with intense dislocation activity in the grain boundary denuded zone resulted in a marked improvement in ductility. Furthermore, the extensive dislocation activity along grain boundary regions ultimately resulted in an intergranular fracture morphology.
- Research Organization:
- Hanford Engineering Development Lab., Richland, WA
- DOE Contract Number:
- DE-AC14-76FFO2170
- OSTI ID:
- 5348983
- Journal Information:
- Metall. Trans., A; (United States), Vol. 11:6
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
22 GENERAL STUDIES OF NUCLEAR REACTORS
INCONEL X750
FRACTURE PROPERTIES
DEFORMATION
GRAIN BOUNDARIES
MORPHOLOGY
REACTOR MATERIALS
REACTORS
STACKING FAULTS
SURFACES
ALLOYS
CHROMIUM ALLOYS
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
INCONEL ALLOYS
IRON ALLOYS
MATERIALS
MECHANICAL PROPERTIES
MICROSTRUCTURE
NICKEL ALLOYS
NICKEL BASE ALLOYS
TITANIUM ALLOYS
360103* - Metals & Alloys- Mechanical Properties
220200 - Nuclear Reactor Technology- Components & Accessories