Issue 77

N. S. Kondratev et alii, Fracture and Structural Integrity, 77 (2026) 230-246; DOI: 10.3221/IGF-ESIS.77.14

Modeling subgrain structure evolution during heat treatment

Nikita S. Kondratev, Dmitry S. Bezverkhy, Matvej N. Baldin Laboratory of Multilevel Structural and Functional Materials Modeling, Perm National Research Polytechnic University, Perm 614990, Russia

kondratev@pstu.ru, http://orcid.org/0000-0002-0261-3017 dsbezverkhijj@pstu.ru, http://orcid.org/0000-0003-3026-8107 mnbaldin@pstu.ru, http://orcid.org/0009-0004-7059-0146

Citation: Kondratev, N., Bezverkhy, D., Baldin, M., Modeling subgrain structure evolution during heat treatment, Fracture and Structural Integrity, 77 (2026) 230-246.

Received: 31.03.2026 Accepted: 27.04.2026 Published: 05.05.2026 Issue: 07.2026

A BSTRACT . This paper presents a novel modification of the multilevel statistical model for describing the subgrain boundary migration that can explicitly account for the topology of subgrain structures in the form of Laguerre polyhedra. The evolution of a representative volume of subgrains during annealing in the temperature range 200 340 − C ° after plastic deformation taking into account competing recovery processes like coalescence and subgrain boundary migration is modeled. The material used in this study is the nickel-based superalloy Inconel 718 with complex hierarchical structure and specific phase composition. The results of modeling the changes in a polyhedral subgrain structure under recovery are presented. The contribution of subgrain coalescence and migration processes to recovery is evaluated. The abnormal growth of subgrains is described by the model, the conditions of its occurrence and implementation are defined. The calculated data demonstrate good agreement with experimental results. K EYWORDS . Static recovery, Subgrain structure, Subboundary migration, Subgrain coalescence, Recrystallization nuclei, Nickel-based superalloy Inconel 718.

Copyright: © 2026 This is an open access article under the terms of the CC-BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

I NTRODUCTION he fabrication of metal and alloy products often involves multi-stage production technologies [1]. In most cases, thermomechanical processing of structural alloy workpieces utilizes pressure processing methods over a wide temperature range [1, 2]. One of the key technological stages is the final annealing process [1, 3]. Annealing involves T

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