Comparative study of microstructure and high temperature low cycle fatigue behaviour of nickel base superalloys Inconel 713LC and MAR-M247

0462761 - ÚFM 2017 RIV CH eng C - Conference Paper (international conference)
Šulák, Ivo - Obrtlík, Karel - Čelko, L.
Comparative study of microstructure and high temperature low cycle fatigue behaviour of nickel base superalloys Inconel 713LC and MAR-M247.
Advances in Fracture and Damage Mechanics XV. Pfaffikon: Trans Tech Publications Ltd, 2016 - (Toribio, J.; Mantič, V.; Sáez, A.; Aliabadi, M.), s. 86-89. Key Engineering Materials, 713. ISBN 978-3-03835-716-2. ISSN 1013-9826.
[FDM 2016 - International Conference on Fracture and Damage Mechanics /15./. Alicante (ES), 14.09.2016-16.09.2016]
R&D Projects: GA ČR(CZ) GA15-20991S; GA TA ČR(CZ) TA04011525
Institutional support: RVO:68081723
Keywords : IN713LC * MAR-M247 * hot isostatic pressing * cyclic stress-strain response * high temperature fatigue life
Subject RIV: JL - Materials Fatigue, Friction Mechanics

The present work is focused on the study of microstructure and low cycle fatigue behavior of the first generation nickel-base superalloy IN 713LC (low carbon) and its promising second generation successor MAR-M247 HIP (hot isostatic pressing) at 900 °C. Microstructure of both alloys was studied by means of scanning electron microscopy (SEM). The microstructure of both materials is characterized by dendritic grains, carbides and casting defects. Size and morphology of precipitates and casting defects were evaluated. Fractographic observations have been made with the aim to reveal the fatigue crack initiation place and relation to the casting defects and material microstructure. Low cycle fatigue tests were conducted on cylindrical specimens in symmetrical push-pull cycle under strain control with constant total strain amplitude and strain rate at 900 °C in air. Hardening/softening curves, cyclic stress-strain curve and fatigue life data of both materials were obtained. Cyclic stress-strain curve of MAR M247 is shifted approximately to 120 MPa higher stress amplitudes in comparison with IN 713LC. Significantly higher fatigue life of MAR-M247 has been observed in Basquin representation. On the other hand IN 713LC shows prolonged lifetime compared with MAR-M247 in the Coffin-Manson representation. Results obtained from high temperature low cycle fatigue tests are discussed.
Permanent Link: http://hdl.handle.net/11104/0262940