Department of Materials, Oxford University, 16 Parks Road, Oxford OX1 3PH, UK.
Scientific Center for Optical and Electron Microscopy, ETH Zürich, Auguste-Piccard-Hof 1, 8093 Zürich, Switzerland.
Science. 2017 Mar 17;355(6330):1196-1199. doi: 10.1126/science.aal2418. Epub 2017 Mar 16.
The design of atomic-scale microstructural traps to limit the diffusion of hydrogen is one key strategy in the development of hydrogen-embrittlement-resistant materials. In the case of bearing steels, an effective trapping mechanism may be the incorporation of finely dispersed V-Mo-Nb carbides in a ferrite matrix. First, we charged a ferritic steel with deuterium by means of electrolytic loading to achieve a high hydrogen concentration. We then immobilized it in the microstructure with a cryogenic transfer protocol before atom probe tomography (APT) analysis. Using APT, we show trapping of hydrogen within the core of these carbides with quantitative composition profiles. Furthermore, with this method the experiment can be feasibly replicated in any APT-equipped laboratory by using a simple cold chain.
设计原子级微观结构陷阱以限制氢的扩散是开发抗氢脆材料的关键策略之一。对于轴承钢，一种有效的捕获机制可能是将细小分散的 V-Mo-Nb 碳化物固溶在铁素体基体中。首先，我们通过电解加载使铁素体钢充氢以达到高氢浓度。然后，我们使用低温传递协议将其在微观结构中固定，然后进行原子探针层析（APT）分析。通过 APT，我们显示了氢在这些碳化物核心内的捕获，并具有定量的组成分布。此外，通过这种方法，任何配备 APT 的实验室都可以使用简单的冷链来复制该实验。
