77 to 1,200 K tensile properties of several wrought superalloys after long-term 1,093 K heat treatments in air and vacuum

Journal Article · Tue Feb 01 00:00:00 EST 1994 · Journal of Materials Engineering and Performance; (United States)

DOI:https://doi.org/10.1007/BF02654504· OSTI ID:6983308

Whittenberger, J D ^[1]

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1. National Aeronautics Space Agency, Cleveland, OH (United States). Lewis Research Center

The 77 to 1,200 K tensile properties of approximately 1.3 mm thick wrought sheet Co-base Haynes alloy 188 and Ni-base Haynes alloy 230 and Inconel 617 have been measured after heat treatment in air and vacuum for periods up to 22,500 h at 1,093 K. Significant changes in structure were produced by prior exposures, including precipitation of second phases and, in the case of heat treatment in air, oxide scale and surface-connected grain boundary pits/oxides, as deep as 50 to 70 [mu]m, in all three superalloys. Due to the geometry of the experiment, the vacuum-exposed samples were protected from loss of volatile elements by evaporation; hence, such specimens were simply given 1,093 K anneals in an innocuous environment, which produced very little surface attack. Compared to the properties of as-received alloys, prior exposure tended to reduce both the yield strength and ultimate tensile strength, with the greatest reductions at 77 and 298 K. The most dramatic effect of heat treatment was found in the low-temperature residual tensile elongation, where decreases from 40 to 5% at 77 K were found. Ductility is the only property that was found to have a consistent dependency on environment, with air exposure always yielding less tensile elongation than vacuum exposure.

• OSTI ID: 6983308
• Journal Information: Journal of Materials Engineering and Performance; (United States), Vol. 3:1; ISSN 1059-9495
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
HAYNES 188 ALLOY
TENSILE PROPERTIES
HEAT RESISTING ALLOYS
INCONEL 617
NICKEL BASE ALLOYS
EXPERIMENTAL DATA
HEAT TREATMENTS
MICROSTRUCTURE
ALLOY-CO36CR22NI22W15FE3
ALLOY-NI54CR22CO13MO9
ALLOYS
ALUMINIUM ADDITIONS
ALUMINIUM ALLOYS
CHROMIUM ALLOYS
COBALT ALLOYS
COBALT BASE ALLOYS
CORROSION RESISTANT ALLOYS
DATA
HAYNES ALLOYS
HEAT RESISTANT MATERIALS
INCONEL ALLOYS
INFORMATION
IRON ALLOYS
LANTHANUM ADDITIONS
LANTHANUM ALLOYS
MATERIALS
MECHANICAL PROPERTIES
MOLYBDENUM ALLOYS
NICKEL ALLOYS
NUMERICAL DATA
RARE EARTH
RARE EARTH ALLOYS
360103* - Metals & Alloys- Mechanical Properties