New Approaches to Understanding Hydrogen Embrittlement of Steels

预计氢气生产、运输和利用方面的重大扩张需要在基础设施方面进行大规模投资。氢经济面临的最大挑战之一是储存和运输。目前的储氢技术要么涉及物理储存系统，如加压储罐(通常由钢制成，可能会因低温温度和氢气暴露而脆化--或两者的协同效应)，要么涉及氢化物等材料，这些材料可以以反应的形式储存氢气，然后需要提取。人们对钢在低温下的氢脆现象知之甚少，缺乏机械方面的洞察力意味着材料选择或定制合金的开发仍然具有挑战性。在室温下抗脆化的钢当然是有的，但价格往往很高，而且它们在低温下的行为还没有得到很好的研究。更好地了解氢在金属中的溶解过程，以及作为氢陷阱位置的微观结构特征的作用，将有助于筛选供氢使用的钢。因此，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-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，我们有机会改变人们对这些特性的理解。这项实验工作将得到数值建模的支持，从而产生用于氢服务的候选钢的特征工作流程。

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.