The predominant role of strain-induced vacancies in hydrogen embrittlement of steels: Overview
The predominant role of strain-induced vacancies in hydrogen embrittlement of steels: Overview
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DOI：
10.1016/j.actamat.2018.12.013
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发表时间：
2019-02-15
期刊：
影响因子：
9.4
通讯作者：
Takai, Kenichi
中科院分区：
文献类型：
--
作者：
Nagumo, Michihiko;Takai, Kenichi
综述了氢促进应变诱导空位产生的机制，即HESIV机制及其在钢的氢脆(HE)中的作用。用最新发展的低温氢热脱附光谱和正电子寿命测量发现了高密度的空位及其聚集。裂纹形核和扩展的促进归因于与强烈应变局部化相关的损伤演化，而HE的特征，如对钢的组织和试验条件的依赖性，与HESIV机制是一致的。空位和氢在早期断裂中分别起主导和辅助作用的实验被设计用来区分它们各自的贡献。多孔材料的本构关系适用于描述HESIV机制对裂纹扩展阻力和应变局部化的力学效应。提出了纳米尺度下的相继空穴形核、长大和连接机制。(C)2018 Acta Materialia Inc.由Elsevier Ltd.出版。保留所有权利。
Recent studies on hydrogen enhancement of the strain-induced generation of vacancies, i.e. the HESIV mechanism, and its role in hydrogen embrittlement (HE) of steels are overviewed. A high density of vacancies and their clustering have been detected by newly developed low temperature hydrogen thermal desorption spectroscopy and positron lifetime measurements. The promotion of crack nucleation and growth is ascribed to the evolution of damage associated with intense strain localization, and characteristic features of HE such as dependence on the microstructures of steels and test conditions are consistent with the HESIV mechanism. The predominant and supplementary roles of vacancies and hydrogen, respectively, in premature fracture are demonstrated by experiments devised to separate each contribution. A constitutive relation for porous materials is applicable to describe mechanistic effects of the HESIV mechanism on crack growth resistance and strain localization. The sequential void nucleation, growth and link mechanism in nanoscale are suggested. (C) 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.