Cyclic axial-torsional deformation behavior of a cobalt-base superalloy

Conference · Sun Nov 01 04:00:00 EST 1992

OSTI ID:7198968

Bonacuse, P J; Kalluri, S

Multiaxial loading, especially at elevated temperature, can cause the inelastic response of a material to differ significantly from that predicted by simple flow rules, i.e., von Mises or Tresca. To quantify some of these differences, the cyclic high-temperature, deformation behavior of a wrought cobalt-based superalloy, Haynes 188, is investigated under combined axial and torsional loads. Haynes 188 is currently used in many aerospace gas turbine and rocket engine applications, e.g., the combustor liner for the T800 turboshaft engine for the RAH-66 Comanche helicopter and the liquid oxygen posts in the main injector of the space shuttle main engine. The deformation behavior of this material is assessed through the examination of hysteresis loops generated from a biaxial fatigue test program. A high-temperature axial, torsional, and combined axial-torsional fatigue data base has been generated on Haynes 188 at 760 C. Cyclic loading tests have been conducted on uniform gauge section tubular specimens in a servohydraulic axial-torsional test rig. Test control and data acquisition were accomplished with a minicomputer. In this paper, the cyclic hardening characteristics and typical hysteresis loops in the axial stress versus axial strain, shear stress versus engineering shear strain, axial strain versus engineering shear strain, and axial stress versus shear stress spaces are presented for cyclic, in-phase and out-of-phase, axial torsional tests. For in-phase tests three different values of the proportionality constant, lambda (ratio of engineering shear strain amplitude to axial strain amplitude), are examined, viz., 0.86, 1.73, and 3.46. In the out-of-phase tests, three different values of the phase angle, phi (between the axial and engineering shear strain waveforms), are studied, viz., 30, 60, and 90 deg with lambda = 1.73.

• Research Organization: National Aeronautics and Space Administration, Cleveland, OH (United States). Lewis Research Center
• OSTI ID: 7198968
• Report Number(s): N-94-28921; NASA-TM--106372; E--8182; NAS--1.15:106372; ARL-MR--113; CONF-9211134--; CNN: NAS3-25266; RTOP 584-03-11
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360103* -- Metals & Alloys-- Mechanical Properties
ALLOY-CO36CR22NI22W15FE3
ALLOYS
CHROMIUM ALLOYS
COBALT ALLOYS
COBALT BASE ALLOYS
CORROSION RESISTANT ALLOYS
HAYNES 188 ALLOY
HAYNES ALLOYS
HEAT RESISTANT MATERIALS
HEAT RESISTING ALLOYS
IRON ALLOYS
LANTHANUM ADDITIONS
LANTHANUM ALLOYS
MATERIALS
MECHANICAL PROPERTIES
RARE EARTH
RARE EARTH ALLOYS
STRAINS
STRESS ANALYSIS
TORSION