Dwell effect on low cycle fatigue behaviour of cast superalloy Inconel 792-5A at 800 °C

0421225 - ÚFM 2014 RIV DE eng C - Conference Paper (international conference)
Šmíd, Miroslav - Obrtlík, Karel - Polák, Jaroslav
Dwell effect on low cycle fatigue behaviour of cast superalloy Inconel 792-5A at 800 °C.
Proceedings of the Seventh International Conference on Low Cycle Fatigue - LCF7. Berlín: DMV, 2013, s. 113-118. ISBN 978-3-9814516-2-7.
[LCF7 - International Conference on Low Cycle Fatigue /7./. Aachen (DE), 09.09.2013-11.09.2013]
R&D Projects: GA ČR(CZ) GAP204/11/1453; GA ČR(CZ) GAP107/11/2065; GA MPO FR-TI4/030
Institutional support: RVO:68081723
Keywords : nickel base superalloy * low cycle fatigue * dwell * high temperature fatigue * surface relief * dislocation structure
Subject RIV: JL - Materials Fatigue, Friction Mechanics

The present paper is focused on the study of the effect of tensile and compressive dwells on the stress-strain behaviour, fatigue life and deformation mechanisms in cast polycrystalline nickel base superalloy Inconel 792-5A at temperature 800 °C in air. Button-end specimens were fatigued with constant strain rate and constant total strain range. Dwell time was 10 minutes. Cyclic hardening/softening curves, stress-strain curves and fatigue life curves have been obtained for continuous cycling and cycling both with tensile and with compressive dwells. Fatigue life curves do not result in any significant reduction of the fatigue life. Surface relief was observed using scanning electron microscopy. It strongly depends on the type of fatigue test and the value of total strain amplitude. Internal structure, studied by transmission electron microscopy, was dependent on the strain amplitude and type of test. Bands of high dislocation density were observed only in continuous cycling.
Permanent Link: http://hdl.handle.net/11104/0228182