PSI - Issue 71

Available online at www.sciencedirect.com

ScienceDirect

Procedia Structural Integrity 71 (2025) 118–125

5 th International Structural Integrity Conference & Exhibition (SICE 2024)

Study of Effect of Hold Time on Low Cycle Fatigue Properties of Alloy 617M Prasanna Dupare a , Atul Ramesh Ballal a , Manjusha Thawre a , Isaac Samuel b , A Nagesha b a Department of Metallurgical & Materials Engineering, Visvesvaraya National Institute of Technology, Nagpur-440010, India b Mechanical Metallurgy Division, Indira Gandhi Center for Atomic Research, Kalpakkam-603102, India Abstract Alloy 617 is a candidate material for components operating at elevated temperatures in Advanced Ultra-Supercritical (AUSC) power plants. Low Cycle Fatigue (LCF) and Creep-Fatigue Interaction (CFI) are crucial considerations for high-temperature applications. Strain-controlled fatigue tests were performed on M16 specimens at temperature 650 ° C and a strain amplitude of ±0.25%, with hold times of 1 minute and 10 minutes with strain rate of 3x10 -3 s -1 . Cyclic stress response (CSR) was recorded for all tests. The introduction of hold time resulted in decreased cyclic life and lowered CSR. Optical and Scanning electron microscope were utilized for microstructure investigation. Fractography revealed transgranular failure under LCF conditions, while a mixed mode of transgranular and intergranular failure was observed in CFI. © 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of SICE 2024 organizers

Keywords: Alloy 617; LCF; CFI; Fractography

Corresponding author. E-mail address: prasannadupare@gmail.com

1. Introduction To meet future energy demands, Advanced Ultra Super-Critical (AUSC) power plant is a promising technology (Chetal et al., 2015). AUSC aims to reduce CO 2 emissions and improve thermal efficiency by operating at higher temperatures and pressures than the ones currently used. AUSC power plants have working temperature of 720 °C and pressure of 35 MPa. Alloy 617 is selected for turbine and boiler tube applications in AUSC plants due to its high-temperature strength, oxidation resistance, and creep resistance (Karnati et al., 2019). Ni and Cr provide resistance to oxidizing environments, while Al and Ti form γ’ precipitates, with Co and Mo contributing to solid solution

2452-3216 © 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of SICE 2024 organizers 10.1016/j.prostr.2025.08.017