Molecular dynamics study of irradiation damage and helium effects in a simplified Fe–Ni–Cr alloy system: Relevant to alloy 800H

IF 1.4 3区物理与天体物理 Q3 INSTRUMENTS & INSTRUMENTATION

Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms Pub Date : 2025-10-04 DOI:10.1016/j.nimb.2025.165871

T.P. Kaloni, I. Cheik Njifon, E. Torres

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Abstract

Fe–Ni–Cr alloy 800H is a critical structural material in nuclear reactors. Under irradiation, it faces significant challenges due to defect formation and Helium (He) generation, which adversely affect its microstructure and durability. In this study, we conducted molecular dynamics simulations of the combined effects of He and irradiation in polycrystalline Fe–Ni–Cr alloy 800H. Our findings show that irradiation induces the transition of the polycrystals into a single crystal. However, increasing the number of grains and He concentration favored the polycrystalline state. We also observe a decrease in the number of dislocations and an increase in large defects with the increase of the He content. Our structural evaluations reveal that He clusters mainly accumulate at those large defects, which are surrounded by dislocation loops. The interplay between the formation of He clusters and irradiation damage results in substantially deteriorating the mechanical properties of Fe–Ni–Cr alloy 800H structures. Our simulations provide valuable insights into the degradation mechanisms under the combined effects of He and irradiation damage.

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简化Fe-Ni-Cr合金体系辐照损伤及氦效应的分子动力学研究：与合金800H相关

铁镍铬合金800H是核反应堆的关键结构材料。在辐照下，由于缺陷的形成和氦（He）的产生，它面临着巨大的挑战，这对其微观结构和耐久性产生不利影响。在本研究中，我们对He和辐照在多晶Fe-Ni-Cr合金800H中的联合效应进行了分子动力学模拟。我们的研究结果表明，辐照诱导多晶转变为单晶。然而，增加晶粒数和He浓度有利于多晶态的形成。我们还观察到，随着He含量的增加，位错数量减少，大缺陷数量增加。我们的结构评价表明，He团簇主要聚集在那些被位错环包围的大缺陷上。He团簇的形成与辐照损伤的相互作用导致Fe-Ni-Cr合金800H组织的力学性能显著恶化。我们的模拟为研究He和辐照损伤联合作用下的降解机制提供了有价值的见解。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms 物理-核科学技术

CiteScore

2.80

自引率

7.70%

发文量

231

审稿时长

1.9 months

期刊介绍： Section B of Nuclear Instruments and Methods in Physics Research covers all aspects of the interaction of energetic beams with atoms, molecules and aggregate forms of matter. This includes ion beam analysis and ion beam modification of materials as well as basic data of importance for these studies. Topics of general interest include: atomic collisions in solids, particle channelling, all aspects of collision cascades, the modification of materials by energetic beams, ion implantation, irradiation - induced changes in materials, the physics and chemistry of beam interactions and the analysis of materials by all forms of energetic radiation. Modification by ion, laser and electron beams for the study of electronic materials, metals, ceramics, insulators, polymers and other important and new materials systems are included. Related studies, such as the application of ion beam analysis to biological, archaeological and geological samples as well as applications to solve problems in planetary science are also welcome. Energetic beams of interest include atomic and molecular ions, neutrons, positrons and muons, plasmas directed at surfaces, electron and photon beams, including laser treated surfaces and studies of solids by photon radiation from rotating anodes, synchrotrons, etc. In addition, the interaction between various forms of radiation and radiation-induced deposition processes are relevant.