PSI - Issue 43

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2022) 000 – 000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2022) 000 – 000

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Procedia Structural Integrity 43 (2023) 209–214

© 2023 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 the responsibility of MSMF10 organizers. © 20 23 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under the responsibility of MSMF10 organizers. Abstract The B1914 superalloy is engaged i the power and aerospace industry as a material for critical hot s ction of gas turbines. Typical findings in these critical components wit high number of operations are damages by low cycle fatigue where high stres es compar ble to the material yield strength are developed due to m chani al load ng or t ermal gradients caus g larg pl tic defo mation. The prese t contribution refers to the high-temperature low cycle fatigue behaviour of polycrystalline nickel-based superalloy B1914. Cylindrical specimens were fatig ed under strain control with constant total strain amplitude in symmetrical cycl ng t 800°C and 900°C in air. T microstructure s ased on a γ matrix (face-centered cubic lattice) with coherent L1 2 γ´ precipitates and γ/γ´ eu ctic. The higher content of g in boundary stabi zing boro allows for low r carbon contents and thu reduces he carbide content that can facilitat fatigue crack initiation. Cyclic h rdening/softenin curves a fatigue life diagrams were determined. A increase in te ting emperatur ccelerated fatigue crack ini ation at grain boundaries associated with carbides. The SEM and TEM analysis of fatigued material further the discussion of fatigue behaviour of the B1914 superalloy. © 20 23 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under the responsibility of MSMF10 organizers. 10th International Conference on Materials Structure and Micromechanics of Fracture High Temperature Fatigue Properties of Boron-doped Superalloy B1914 Ivo Šulák a * , Karel Hrbáček a , Karel Obrtlík a a Institute of Physics of Materials, Czech Academy of Sciences, Žižkova 22, Brno 616 00, Czech Republic Abstract The B1914 superalloy is engaged in the power and aerospace industry as a material for critical hot section of gas turbines. Typical findings in these critical components with a high number of operations are damages by low cycle fatigue where high stresses comparable to the material yield strength are developed due to mechanical loading or thermal gradients causing large plastic deformation. The present contribution refers to the high-temperature low cycle fatigue behaviour of polycrystalline nickel-based superalloy B1914. Cylindrical specimens were fatigued under strain control with constant total strain amplitude in symmetrical cycl ing at 800°C and 900°C in air. The microstructure is based on a γ matrix (face-centered cubic lattice) with coherent L1 2 γ´ precipitates and γ/γ´ eutectic. The higher content of grain boundary stabilizing boron allows for lower carbon contents and thus reduces the carbide content that can facilitate fatigue crack initiation. Cyclic hardening/softening curves and fatigue life diagrams were determined. An increase in testing temperature accelerated fatigue crack initiation at grain boundaries associated with carbides. The SEM and TEM analysis of fatigued material further the discussion of fatigue behaviour of the B1914 superalloy. 10th International Conference on Materials Structure and Micromechanics of Fracture High Temperature Fatigue Properties of Boron-doped Superalloy B1914 Ivo Šulák a * , Karel Hrbáček a , Karel Obrtlík a a Institute of Physics of Materials, Czech Academy of Sciences, Žižkova 22, Brno 616 00, Czech Republic Keywords: Fatigue hardening/softening curves; Cyclic stress-strain curves; Fatigue life curves; precipitates; SEM; TEM. Keywords: Fatigue hardening/softening curves; Cyclic stress-strain curves; Fatigue life curves; precipitates; SEM; TEM. 1. Introduction Polycrystalline nickel-based superalloys are extraordinary high-temperature materials that are commonly used up to 90% of their actual melting point. Due to their outstanding combination of high-temperature mechanical properties, good oxidation resistance, and excellent surface stability, they are utilized in hot-section of contemporary aircraft 1. Introduction Polycrystalline nickel-based superalloys are extraordinary high-temperature materials that are commonly used up to 90% of their actual melting point. Due to their outstanding combination of hig -temperature mechanical properties, good oxidation resistance, and excellent surface stability, they are utilized in hot-section of contemporary aircraft

* Corresponding author. Tel.: +420-532-290-343. E-mail address: sulak@ipm.cz * Correspon ing a thor. Tel.: +420-532-290-343. E-mail address: sulak@ipm.cz

2452-3216 © 2023 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 the responsibility of MSMF10 organizers. 2452-3216 © 2023 The Authors. Published by Elsevier B.V. This is an ope access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under the responsibility of MSMF10 organizers.

2452-3216 © 2023 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 the responsibility of MSMF10 organizers. 10.1016/j.prostr.2022.12.260