Long-time microstructural effects in alloy 718 turbine disks

Journal Article · Sat Dec 01 04:00:00 EST 1990 · MIAC Newsletter; (USA)

OSTI ID:5750238

Radavich, J F ^[1]

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1. Purdue Univ., West Lafayette, IN (USA)

A comprehensive study of superalloy components which have been exposed for long periods to elevated temperatures, in order to characterize the structural changes occurring in gas turbine components operating for up to 45,000 hrs, has given attention to the most widely used of the gas turbine superalloys, 718. SEM and XRD analyses of two 718 disks with 15,000 and 28,000 hrs of operation indicate, in the latter case, substantial departures from the initial microstructure of the disk outer rim. The fine precipitation of gamma-prime and gamma double-prime phases which initially imparted strengthening had grown during service into spheroidal gamma-prime particles and plates of delta phase; this change is accompanied by a softening of the alloy.

• OSTI ID: 5750238
• Journal Information: MIAC Newsletter; (USA), Journal Name: MIAC Newsletter; (USA) Vol. 1; ISSN MNEWE
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
330103 -- Internal Combustion Engines-- Turbine
36 MATERIALS SCIENCE
360102* -- Metals & Alloys-- Structure & Phase Studies
AGING
ALLOYS
CRYSTAL STRUCTURE
ENGINES
GAS TURBINE ENGINES
HEAT ENGINES
HEAT RESISTANT MATERIALS
HEAT RESISTING ALLOYS
HEAT TREATMENTS
INTERNAL COMBUSTION ENGINES
MATERIALS
MECHANICAL PROPERTIES
MICROSTRUCTURE
NICKEL ALLOYS
NICKEL BASE ALLOYS
SERVICE LIFE
STRESSES
THERMAL STRESSES
TURBINE BLADES