Dear Colleagues,

Hydrogen embrittlement (HE), which corresponds to the abrupt loss of a material’s load-bearing capacity in presence of H, is often responsible for catastrophic and unpredictable failure of large-scale engineering structures (e.g., bridges, pipelines, vessels and chemical infrastructures). This embrittlement phenomenon occurs in many metallic materials including steels, titanium alloys, nickel-, cobalt- and iron-based superalloys, aluminum alloys and etc. High-strength alloys are particularly prone to H embrittlement, due to (a) H is the smallest atom with an ubiquitous nature, thus its ingress into a material is normally difficult to avoid and (b) an amount of H even below 1 wt ppm can result in a serious embrittlement effect in these materials. Therefore, H embrittlement basically threatens any industries (e.g., automotive and aerospace) that aim to use high-strength alloys to make lightweight structural components, and with that, may set an abrupt halt to some of the pending infrastructures needed for a hydrogen economy. It is thus crucial to understand the mechanisms as well as to explore solutions for improving materials’ resistance to H.

This Research Topic aims to cover all experimental and modeling studies associated with H embrittlement, with particular focuses on three aspects. (a) Fundamental investigations towards the understanding of H embrittlement mechanisms. This includes H trapping, interaction between H and lattice defects (e.g., dislocations, interfaces and vacancies), and H-induced or assisted damage mechanisms. (b) Characterization of H diffusion and H embrittlement phenomenon in various types of metallic materials. The latter includes but is not limited to H-induced degradation of mechanical properties, H-induced microstructure change, H-induced damages and the resulting fractography. (c) Novel technical, alloying and microstructural concepts against H embrittlement. The state-of-the-art research, development, and current challenges in the field of H embrittlement will be highlighted in this Research Topic, which is helpful to guide future research efforts.

Dr. Binhan Sun
Prof. Clodualdo Aranas
Dr. Yu Bai
Guest Editors

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• hydrogen embrittlement
• hydrogen diffusion and trapping
• fracture mechanics
• steels
• microstructure
• damage
• characterization
• mechanical property