PSI - Issue 20

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2018) 000 – 000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2018) 000 – 000

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Procedia Structural Integrity 20 (2019) 24–29

1st International Conference on Integrity and Lifetime in Extreme Environment (ILEE-2019) Kinetics of brittle fracture in metals under the influence of hydrogen Valeriy Lepov a,b, *, Ekaterina Arkhanelskaja c , Valentina Achikasova a a Larionov’s Institute of Pysical-Technical Problems of the North SB RAS, 1 Oktyabrskaja str., 677891, Yakutsk, Russia 1st International Conference on Integrity and Lifetime in Extreme Environment (ILEE-2019) Kinetics of brittle fracture in metals under the influence of hydrogen Valeriy Lepov a,b, *, Ekaterina Arkhanelskaja c , Valentina Achikasova a a Larionov’s Institut of Pysi al-T chnical Problems of the North SB RAS, 1 Oktyabrskaja str., 677891, Y kutsk, Russia b cademy of Science of Republic of Sakha (Yakutia), 33 Lenina av., 007, k tsk, ssi c Ammosov’s North Eastern Federal University, 33 Belinskogo str., 677891, Yakutsk, Russia Abstract Some aspects of damage accumulation mo eling and brittle fracture proc sses mechanisms under the co bined effect of mechanical l ading and hydrogen has been discussed i the article. New mechanism of brittle fracture for metallic materials based on dislocation and phonon structure fingerprints and lattice hydrog n content under th static a d dy amic loading at low temperature condition has be proposed. The mecha ism based on theoretical research and experimental and numerical studies. The experim nts include the energy spectrum of internal friction determination and impact toughness testing for low-temperature brittle-ductile transition revealing. The numerical study based on damage accumulation modeling under th influence of up-hill diffusion in the elastic-plastic problem of solid state by finite element method. A new si ple activation model of low temperature and hydrogen influence on damage accumulation process has been proposed. The model shows the rate of damage strong dependence f stress level and ydrogen content, a d test temperature. The combination of low temperature and high hydrogen content is most dangerous, so the weld structures in extreme environment such as the Arctic and Subarctic regions hav a high risk f bre kage. So it is possibl to estimate the en rgy and phonon sp ctrum of cryst l lattice, and predict t e prop rti s of microcrystalline and nanostructured materials with the high cold-short threshold on the base of such the approach. There are the recommendations propose to improve the cold resistance of steels and alloys by controlling the characteristics of the dislocation structure of new materials with polycrystalline and ultrafine-grained structure. b Academy of Science of Republic of Sakha (Yakutia), 33 Lenina av., 677007, Yakutsk, Russia c Ammosov’s North Eastern Federal University, 33 Belinskogo str., 677891, Yakutsk, Russia Abstract Some aspects of damage accumulation modeling and brittle fracture processes mechanisms under the combined effect of mechanical loading and hydrogen has been discussed in the article. New mechanism of brittle fracture for metallic materials based on dislocation and phonon structure fingerprints and lattice hydrogen content under the static and dynamic loading at low temperature condition has been proposed. The mechanism based on theoretical research and experimental and numerical studies. The experiments include the energy spectrum of internal friction determination and impact toughness testing for low-temperature brittle-ductile transition revealing. The numerical study based on damage accumulation modeling under the influence of up-hill diffusion in the elastic-plastic problem of solid state by finite element method. A new simple activation model of low temperature and hydrogen influence on damage accumulation process has been proposed. The model shows the rate of damage strong dependence of stress level and hydrogen content, and test temperature. The combination of low temperature and high hydrogen content is most dangerous, so the weld structures in extreme environment such as the Arctic and Subarctic regions have a high risk of breakage. So it is possible to estimate the energy and phonon spectrum of crystal lattice, and predict the properties of microcrystalline and nanostructured materials with the high cold-short threshold on the base of such the approach. There are the recommendations propose to improve the cold resistance of steels and alloys by controlling the characteristics of the dislocation structure of new materials with polycrystalline and ultrafine-grained structure.

© 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ILEE-2019 organizers © 2019 The Author(s). Published by Elsevier B.V. Peer-review under responsibility of the ILEE-2019 organizers © 2019 The Author(s). Published by Elsevier B.V. Peer-review under responsibility of the ILEE-2019 organizers

Keywords: damage; modeling; cold resistance; low temperature ductile-brittle transition; fluctuation; lattice hydrogen; dislocation; risk of breakage; cold-short threshold K ywords: damage; modeling; cold resistance; low temperature ductile-brittle transition; fluctuation; lattice hydrogen; dislocation; risk of breakage; cold-short threshold

2452-3216 © 2019 The Author(s). Published by Elsevier B.V. Peer-review under responsibility of the ILEE-2019 organizers 2452 3216 © 2019 Th Author(s). Publis d by lsevier B.V. Peer-review under responsibility of the ILEE-2019 organizers * Correspon ing auth r. Tel.: +7-411-2390-578; fax: +7-411-2390-599. E-mail address: lepov@iptpn.ysn.ru * Corresponding author. Tel.: +7-411-2390-578; fax: +7-411-2390-599. E-mail address: lepov@iptpn.ysn.ru

2452-3216 © 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ILEE-2019 organizers 10.1016/j.prostr.2019.12.110