PSI - Issue 72

Available online at www.sciencedirect.com

ScienceDirect

Procedia Structural Integrity 72 (2025) 265–269

Keywords: Beremin model; brittle fracture; fracture mechanics; Weibull statistics; python 1. Introduction This paper presents a subtask of the work done in the Fractesus project, which aimed to analyze the applicability of small sized test specimens in fracture mechanics evaluations. The project was divided into Work Packages, of which this study was a part of WP4, which was the numerical support and analysis of the physical measurement results. The ductile-to-brittle transition is an important phenomenon in steels where temperatures can vary with time in use. It is especially pronounced in nuclear power plants for various reasons. During its lifetime, the material Abstract This presentation explores the ductile-to-brittle transition in steels, focusing on determining parameters for the Beremin model to assess brittle cleavage fracture probability. The study highlights the use of sub-sized compact tensile (CT) test specimens, especially 0.16T-CT specimens, due to the limited availability of standardized 1T-CT specimens in nuclear power plant surveillance programs. Fracture toughness measurements were taken for three RPV steels (15Kh2MFAA, 73W, JRQ) at different temperatures, and finite element simulations validated the force-J-integral curves. The Beremin model parameters were optimized using these measurements. Valid parameter combinations were mainly determined for 15KH2MFAA. © 2026 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 Aleksandar Sedmak, Branislav Djordjevic, Simon Sedmak Dr. Simon Sedmak, ssedmak@mas.bg.ac.rs, Innovation Center of Faculty of Mechanical Engineering, Belgrade, Serbia 12th Annual Conference of Society for Structural Integrity and Life (DIVK12) Beremin parameter determination for 15Kh2MFAA steel for standard and subsized specimens Péter Ungár a, *, Zoltán Bézi a a AEMI Atomic Energy Engineering Company Ltd., Miskolc, Hungary

* Corresponding author. E-mail address: ungar.peter@aemi-tech.hu

2452-3216 © 2026 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 Aleksandar Sedmak, Branislav Djordjevic, Simon Sedmak Dr. Simon Sedmak, ssedmak@mas.bg.ac.rs, Innovation Center of Faculty of Mechanical Engineering, Belgrade, Serbia 10.1016/j.prostr.2025.08.102