PSI - Issue 59

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect StructuralIntegrity Procedia 00 (2023) 000 – 000 Available online at www.sciencedirect.com ScienceDirect StructuralIntegrity Procedia 00 (2023) 000 – 000

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Procedia Structural Integrity 59 (2024) 378–384

© 2024 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 DMDP 2023 Organizers © 2024 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 DMDP 2023 Organizers Abstract The influence of the surface nanocrystalline structure (NCS) of the alloy structural steel fabricated by mechanical pulse treatment (MPT) on the contact durability in oil and tap water was investigated and compared with that for steels treated with cementation, quenching and tempering at 150°C, which usually used for such alloy steel. MPT was performed using different coolants and technological fluids (TF) during MPT. It was revealed that surface NCS formed by MPT in TF of industrial oil and an aqueous solution of emulsol increased contact durability of the steel in oil in approximately 2 times compared to cementation with further quenching and low-tempering; the contact durability of the same specimens in water remained changeless. MPT in air resulted in the highest contact durability; however, it leads to a decrease in surface roughness and is technologically unsuitable. The contact durability in the oil is significantly higher compared to that in the tap water. The components of the technological and test environments (hydrogen, carbon, oxygen, etc.) get into the surface layers during MPT and tests, modify them and significantly influence on the service life. © 2024 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 DMDP 2023 Organizers VII International Conference “In -service Damage of Materials: Diagnostics and Prediction ” (DMDP 2023) Improvement of durability of structural steels under high contact loading by nanostructuring frictional treatment Olha Maksymiv a *, Volodymyr Kyryliv a , Borys Chaikovs ’kyi b , Olha Zvirko a a Karpenko Physico-Mechanical Institute of the National Academy of Sciences of Ukraine, 5, Naukova St., 79060 Lviv, Ukraine b Stepan Gzhytskyi National University of Veterinary Medecine and Biotechnologies, 5, Pekarska St., 79010 Lviv, Ukraine Abstract The influence of the surface nanocrystalline structure (NCS) of the alloy structural steel fabricated by mechanical pulse treatment (MPT) on the contact durability in oil and tap water was investigated and compared with that for steels treated with cementation, quenching and tempering at 150°C, which usually used for such alloy steel. MPT was performed using different coolants and technological fluids (TF) during MPT. It was revealed that surface NCS formed by MPT in TF of industrial oil and an aqueous solution of emulsol increased contact durability of the steel in oil in approximately 2 times compared to cementation with further quenching and low-tempering; the contact durability of the same specimens in water remained changeless. MPT in air resulted in the highest contact durability; however, it leads to a decrease in surface roughness and is technologically unsuitable. The contact durability in the oil is significantly higher compared to that in the tap water. The components of the technological and test environments (hydrogen, carbon, oxygen, etc.) get into the surface layers during MPT and tests, modify them and significantly influence on the service life. VII International Conference “In -service Damage of Materials: Diagnostics and Prediction ” (DMDP 2023) Improvement of durability of structural steels under high contact loading by nanostructuring frictional treatment Olha Maksymiv a *, Volodymyr Kyryliv a , Borys Chaikovs ’kyi b , Olha Zvirko a a Karpenko Physico-Mechanical Institute of the National Academy of Sciences of Ukraine, 5, Naukova St., 79060 Lviv, Ukraine b Stepan Gzhytskyi National University of Veterinary Medecine and Biotechnologies, 5, Pekarska St., 79010 Lviv, Ukraine

Keywords: Contact fatigue; alloy steel; nanocrystalline structure; mechanical pulse treatment; drilling bit. Keywords: Contact fatigue; alloy steel; nanocrystalline structure; mechanical pulse treatment; drilling bit.

* Corresponding author. Tel.: +380-3229-6211. E-mail address: okyryliv@yahoo.com * Corresponding author. Tel.: +380-3229-6211. E-mail address: okyryliv@yahoo.com

2452-3216 © 2024 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 DMDP 2023 Organizers 2452-3216 © 2024 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 DMDP 2023 Organizers

2452-3216 © 2024 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 DMDP 2023 Organizers 10.1016/j.prostr.2024.04.054