New Approaches to Understanding Hydrogen Embrittlement of Steels

氢气生产、运输和利用的预期大规模扩张需要对基础设施进行大规模投资。氢经济的最大挑战之一是储存和运输。目前的储氢技术涉及物理存储系统，如加压罐（通常由钢制成，可能会因低温和氢气暴露而脆化-或两者的协同效应）或材料，如可以以反应形式存储氢气的氢气，然后需要提取。人们对钢在低温下的氢脆了解甚少，缺乏机理见解意味着材料选择或定制合金开发仍然具有挑战性。在室温下抗脆化的钢当然是可用的，但往往是昂贵的，并且它们在低温下的行为还没有得到很好的探索。对氢在金属中溶解过程的基本理解的提高，以及微观结构特征作为氢陷阱位点的作用，将有助于筛选氢服务用钢。因此，该iCASE项目将专注于氢在不同钢中的溶解、扩散和分布的实验研究，并在低温条件下对钢进行研究和表征。使用帝国理工学院的新实验设施，我们有机会在理解这些属性方面创造一个台阶式的变化。实验工作将得到数值建模的支持，从而形成表征氢服务候选钢的工作流程。

The anticipated major expansion in hydrogen production, transportation and utilisation calls for massive investments in infrastructure. One of the biggest challenges of the hydrogen economy is storage and transport. Current hydrogen storage technology involves either physical storage systems such as pressurised canisters (typically made from steel, which may be embrittled by the cryogenic temperatures and hydrogen exposures- or the synergistic effects of both) or materials such as hydrides which can store hydrogen in a reacted form, that will then need to be extracted. Hydrogen embrittlement in steel at cryogenic temperatures is poorly understood - and lack of mechanistic insights means that material selection or bespoke alloy development remains challenging. Steels that are resistant to embrittlement at room temperature are certainly available but tend to be expensive, and their behaviour under cryogenic temperatures has not been well-explored. Improved fundamental understanding of the processes of hydrogen dissolution in the metal, and the role of microstructural features that act as hydrogen trap sites, will assist in screening steels for hydrogen service. This iCASE project will therefore focus on the experimental investigation of hydrogen dissolution, diffusion and distribution in different steels - with the steels studied and characterized under cryo-conditions. Using new experimental facilities at Imperial, we have a chance to create a step-change in understanding of the properties. The experimental work will be supported by numerical modelling, leading to a workflow for characterising candidate steels for hydrogen service.