Low strain, long life creep fatigue of AF2-1DA and INCO 718

Technical Report · Fri Apr 01 04:00:00 EST 1983

OSTI ID:7140674

Thakker, A B; Cowles, B A

Two aircraft turbine disk alloys, GATORIZED AF2-DA and INCO 718 were evaluated for their low strain long life creep-fatigue behavior. Static (tensile and creep rupture) and cyclic properties of both alloys were characterized. The cntrolled strain LCF tests were conducted at 760 C (1400 F) and 649 C (1200 F) for AF2-1DA and INCO 718, respectively. Hold times were varied for tensile, compressive and tensile/compressive strain dwell (relaxation) tests. Stress (creep) hold behavior of AF2-1DA was also evaluated. Generally, INCO 718 exhibited more pronounced reduction in cyclic life due to hold than AF2-1DA. The percent reduction in life for both alloys for strain dwell tests was greater at low strain ranges (longer life regime). Changing hold time from 0 to 0.5, 2.0 and 15.0 min. resulted in corresponding reductions in life. The continuous cycle and cyclic/dwell initiation failure mechanism was predominantly transgranular for AF2-1DA and intergranular for INCO 718.

• Research Organization: Pratt and Whitney Aircraft Group, West Palm Beach, FL (USA)
• OSTI ID: 7140674
• Report Number(s): N-8410268; NASA-CR-167989
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360103* -- Metals & Alloys-- Mechanical Properties
ALLOYS
CHEMICAL COMPOSITION
CHROMIUM ALLOYS
CREEP
ENGINES
GAS TURBINE ENGINES
HEAT ENGINES
INCONEL 718
INCONEL ALLOYS
INTERNAL COMBUSTION ENGINES
MECHANICAL PROPERTIES
MOLYBDENUM ALLOYS
NICKEL ALLOYS
NICKEL BASE ALLOYS
NIOBIUM ALLOYS
STRAINS
TEMPERATURE DEPENDENCE