Hydrogen dissolved in metals as a result of internal and external hydrogen can affect the mechanical properties of the metals, principally through the interactions between hydrogen and material defects. Multiple phenomena such as hydrogen dissolution, hydrogen diffusion, hydrogen redistribution and hydrogen interactions with vacancies, dislocations, grain boundaries and other phase interfaces are involved in this process. Consequently, several hydrogen embrittlement (HE) mechanisms have been successively proposed to explain the HE phenomena, with the hydrogen-enhanced decohesion mechanism, hydrogen-enhanced localized plasticity mechanism and hydrogen-enhanced strain-induced vacancies being some of the most important. Additionally, to reduce the risk of HE for engineering structural materials in service, surface treatments and microstructural optimization of the alloys have been suggested. In this review, we report on the progress of the studies on HE in metals, with a particular focus on steels. It focuses on four aspects: (1) hydrogen diffusion behavior; (2) hydrogen characterization methods; (3) HE mechanisms; and (4) the prevention of HE. The strengths and weaknesses of the current HE mechanisms and HE prevention methods are discussed, and specific research directions for further investigation of fundamental HE mechanisms and methods for preventing HE failure are identified.

中文翻译：

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金属中氢脆的研究：氢扩散，氢表征，氢脆机理与预防

由于内在和外在的氢而溶解在金属中的氢会影响金属的机械性能，主要是通过氢与材料缺陷之间的相互作用。该过程涉及多种现象，例如氢溶解，氢扩散，氢再分布以及氢与空位，位错，晶界和其他相界面的相互作用。因此，已经提出了几种氢脆（HE）机理来解释HE现象，其中最重要的是氢增强的脱粘机理，氢增强的局部可塑性机制和氢增强的应变诱发的空位。此外，为了降低使用中的工程结构材料的HE风险，已经提出了合金的表面处理和微观结构优化。在这篇综述中，我们报告了有关金属中HE的研究进展，特别是针对钢铁的研究。它集中在四个方面：（1）氢的扩散行为；（2）氢的表征方法；（3）HE机制；（4）预防HE。讨论了当前HE机制和HE预防方法的优缺点，并确定了进一步研究基础HE机制和预防HE失败方法的具体研究方向。（4）预防HE。讨论了当前HE机制和HE预防方法的优缺点，并确定了进一步研究基础HE机制和预防HE失败方法的具体研究方向。（4）预防HE。讨论了当前HE机制和HE预防方法的优缺点，并确定了进一步研究基础HE机制和预防HE失败方法的具体研究方向。