PSI - Issue 23

Available online at www.sciencedirect.com Available online at www.sciencedirect.com

ScienceDirect ScienceDirect

Available online at www.sciencedirect.com Structural Integrity Procedia 00 (2019) 000 – 000 Structural Integrity Procedia 00 (2019) 000 – 000

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

ScienceDirect

Procedia Structural Integrity 23 (2019) 413–418

© 2019 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 responsibility of the scientific committee of the ICMSMF organizers © 2019 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 responsibility of the scientific committee of the IC MSMF organizers. stress th  a correct quantification of the temperature effect on fracture toughness values C K I and proper prediction of its scatter limits in transition region is possible. In particular, it is important to take into ccount the threshold stress th  when predicting the lower envelope curve for fracture toughness C K I , i.e. the C K I value corresponding to a total probability of 5%. © 2019 The Authors.Published by Els vier .V. This is an ope acces article under CC BY-NC-ND lic nse (http://creativecommon org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the scientific committee of the IC MSMF organizers. The physical nature of cleavage threshold stress th  was considered and the technique for its experimental determination was developed. By applying data for reactor pressure vessel steel and cast low-alloyed manganese steel, it is shown that ignoring the value of th  gives rise to an 1.5-2 times overestimation of the shape parameter m . Within the framework of the suggested alternative of the Local Approach, temperature dependences of fracture toughness C K I for probabilities of 5%, 50% and 95% were obtained for the steels. Accounting for the threshold stress th  a correct quantification of the temperature effect on fracture toughness values C K I and proper prediction of its scatter limits in transition region is possible. In particular, it is important to take into account the threshold stress th  when predicting the lower envelope curve for fracture toughness C K I , i.e. the C K I value corresponding to a total probability of 5%. The physical nature of cleavage threshold stress th  was considered and the technique for its experimental determination was devel ped. By applying data for react r pressure vessel st el and cast low-alloyed manganese steel, it is shown that ignoring the value of th  gives rise to an 1.5-2 times overestimation of the shape parameter m . Withi the framework of the suggested alternative of the L cal Appr ac , temperature dependences of fracture toughness C K I for probabilities of 5%, 50% and 95% were obtained for the steels. Accounting for the threshold 9th International Conference on Materials Structure and Micromechanics of Fracture Threshold fracture stress: theory and application Sergiy Kotrechko a,b *, Oleksandra Zatsarna a , Vladislav Koz á k c , Ivo Dlouh ý c a G.V. Kurdyumov Institute for Metal Physics, National Academy of Sciences of Ukraine, 36, Acad. Vernadsky Blvd., UA-0380 Kyiv, Ukraine b National Technical University of Ukraine “Igor Sikorsky Kyiv Polytechnic Institute” 37, Prosp. Peremohy UA-03056 Kyiv, Ukraine c Institute of Physics of Materials, Academy of Sciences of CR, Zizkova 22, Brno, Czech Republic 9th International Conference on Materials Structure and Micromechanics of Fracture Threshold fracture stress: theory and application Sergiy Kotrechko a,b *, Oleksandra Zatsarna a , Vladislav Koz á k c , Ivo Dlouh ý c a G.V. Kurdyumov I stitute for Metal Physics, Nati nal Academ of Sciences of Ukrain , 36, Acad. Vernadsky Blvd., UA-0380 Kyiv, Ukraine b National Technical University of Ukraine “Igor Sikorsky K iv Polyte hnic Institute” 37, Prosp. Peremohy UA-03056 Kyiv, Ukraine c Institute of Physics of Materials, Academy of Sciences of CR, Zizkova 22, Brno, Czech Republic Abstract Abstract

Keywords: threshold stress; Local Approach; fracture toughness;Weibull parameters; crack nuclei;RPV steel; Keywords: threshold stress; Local Approach; fracture toughness;Weibull parameters; crack nuclei;RPV steel;

Local Approach (LA) to cleavage fracture is an interdisciplinary concept enabling to predict unstable fracture of a pre-cracked body, using a local criterion for initiating a cleavage fracture in the vicinity of a crack/notch. In general, it was assumed that the LA would place fracture mechanics on a strong physical basis. Over the past three Lo al Approach (LA) to cleav ge fracture is a interdisciplin ry concept enabling to predict unstable frac ure of a pre-cracked body, using a local criterion for initiating a leavage fr cture in the vicinity of a crack/notch. In general, it was assumed that the LA would place fracture mechanics on a strong physical basis. Over the past three

* Corresponding author. Tel.:+3-804-424-1352; fax: +3-804-424-2561. E-mail address: serkotr@gmail.com * Correspon ing author. Tel.:+3-804-424-1352; fax: +3-804-424-2561. E-mail address: serkotr@gmail.com

2452-3216 © 2019 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 responsibility of the scientific committee of the IC MSMF organizers. 2452-3216 © 2019 The Authors. Published by Elsevier B.V. This is an ope acces article under CC BY-NC-ND lic nse (http://creativecommon org/licenses/by-nc-nd/4.0/)

Peer-review under responsibility of the scientific committee of the IC MSMF organizers.

2452-3216 © 2019 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 responsibility of the scientific committee of the ICMSMF organizers 10.1016/j.prostr.2020.01.122