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

www.elsevier.com/locate/procedia www.elsevier.com/locate/procedia

ScienceDirect

Procedia Structural Integrity 43 (2023) 228–233

© 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. © 2023 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 paper show that the influenc of plastic strai and temperature on the rate of cra k nuc ei (CN) forma ion is a crucial factor controlling the shape of th temperature d pendence of fracture toughn ss and its scat er limits. Within th fra ework of the microscopic mod l described, it is xplained that the dep ndence of the incompatibili y of micr plastic def mation at grain boundaries r interfaces on the value of plastic strain and temperature is the reason for the eff ct of these factors on the rate of CN formation. The depen c es of the CN bulk density on temperature and plastic stra n are given. In the latter se, a non monotonic change in CN density is observed. The maximum intensity of CN formation is observed when the critical value of pl stic strain is reached. For ferritic structur l steels, this strain is about 2%. Using reactor pressure v ssel steel and cast manganese steel as examples, it is shown that not taking these effects into acc nt in the local fracture approach leads to considerable errors in the prediction of the temperature dependence of the fracture toughness and its scatter limits. © 2023 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 Micromechanical aspects of the effect of temperature and local plastic strain magnitude on the fracture toughness of ferrite steels Sergiy Kotrechko a,b, * , Vladislav Kozák c , Oleksandra Zatsarna a , Galyna Zimina a , Nataliya Stetsenko a , and Ivo Dlouhý c,d a G.V. Kurdyumov Institute for Metal Physics, National Academy of Sciences of Ukraine, 36, Academician Vernadsky Blvd., UA-0380 Kyiv, Ukraine b National Technical University of Ukraine “Igor Sikorsky Kyiv Polytechnic Institute” 37, Peremohy Ave. UA -03056 Kyiv, Ukraine c Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Zizkova 22, 61600 Brno, Czech Republic d Institute of Materials Science and Engineering, Faculty of Mechanical Engineering, Brno University of Technology, Technicka 2, 61669 Brno, Czech Republic Abstract The paper shows that the influence of plastic strain and temperature on the rate of crack nuclei (CN) formation is a crucial factor controlling the shape of the temperature dependence of fracture toughness and its scatter limits. Within the framework of the microscopic model described, it is explained that the dependence of the incompatibility of microplastic deformation at grain boundaries or interfaces on the value of plastic strain and temperature is the reason for the effect of these factors on the rate of CN formation. The dependencies of the CN bulk density on temperature and plastic strain are given. In the latter case, a non monotonic change in CN density is observed. The maximum intensity of CN formation is observed when the critical value of plastic strain is reached. For ferritic structural steels, this strain is about 2%. Using reactor pressure vessel steel and cast manganese steel as examples, it is shown that not taking these effects into account in the local fracture approach leads to considerable errors in the prediction of the temperature dependence of the fracture toughness and its scatter limits. 10th International Conference on Materials Structure and Micromechanics of Fracture Micromechanical aspects of the effect of temperature and local plastic strain magnitude on the fracture toughness of ferrite steels Sergiy Kotrechko a,b, * , Vladislav Kozák c , Oleksandra Zatsarna a , Galyna Zimina a , Nataliya Stetsenko a , and Ivo Dlouhý c,d a G.V. Kurdyumov Institute for Metal Physics, National Academy of Sc ences of Ukraine, 36, Academician Vernadsky Blvd., UA-0380 Kyiv, Ukraine b National Technical University of Ukraine “Igor Sikorsky Kyiv Polytechnic Institute” 37, Peremohy Ave. UA -03056 Kyiv, Ukraine c Institute of Physics of Materials, Academy of Sci nces of the Czech Republic, Zizkova 22, 61600 Brno, Cz Republic d Institute of Materials Science and Engineering, Faculty of Mechanical Engineering, Brno University of Technology, Technicka 2, 61669 Brno, Czech Republic

Keywords: Fracture toughness; Ductile-to-brittle transition; Local approach to fracture; Crack nuclei, Micromechanism. Keywords: Fracture toughness; Ductile-to-brittle transition; Local approach to fracture; Crack nuclei, Micromechanism.

* Corresponding author. Tel.: +38 044 4241352; fax: +38 044 4242561. E-mail address: serkotr@gmail.com * Correspon ing author. Tel.: +38 044 4241352; fax: +38 044 4242561. E-mail address: serkotr@gmail.com

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.2022.12.263