Interaction of hydrogen and fatigue on structural integrity of pipelines for hydrogen transport

氢被认为在能源转型和实现2050年净零排放目标方面发挥着关键作用。氢气输送是氢经济整个价值链中不可或缺的一部分，其中管道提供了一种经济高效的氢气输送方式。特别是，重新利用现有的天然气管道是“输送大量氢气的低成本选择”。对于氢气管道运输来说，安全是最重要的。高压氢气环境下，钢管道可能会发生氢脆（HE），破坏结构完整性并导致管道故障。同时，天然气管道通常经历频繁的压力波动，诱发循环载荷，导致管道疲劳。目前，人们对氢在疲劳开裂中的作用还没有完全了解。有时，会得到有争议的结果。钢在循环荷载作用下的氢吸附行为研究很少。拟议的国际合作的目标是研究高压氢气环境下氢气和疲劳对钢管道结构完整性的相互作用，填补知识空白，并为管道安全输送氢气提供技术建议。该研究将研究氢气在管道钢疲劳开裂中的作用，以及在管道运行条件下（如压力波动幅度和频率、温度、内压、氢气/天然气混合比和钢级），循环加载对钢中氢原子渗透和局部俘获的影响。该项目将在管道HE和疲劳研究方面开展国际合作。这些成果将有助于加速实现氢经济，促进全球能源转型和脱碳，使加拿大在氢管道技术方面处于世界领先地位。

Hydrogen is believed to play a critical role in energy transition and achievement of the 2050 net-zero emission goal. Hydrogen delivery is integral to the entire value chain of hydrogen economy, where pipelines provide an economic and efficient means to transport hydrogen. Particularly, repurposing existing natural gas pipelines is a "low-cost option for delivering large volumes of hydrogen".Safety is paramount for hydrogen transport by pipelines. Hydrogen embrittlement (HE) can potentially occur on steel pipelines in high-pressure hydrogen gas environments, compromising structural integrity and causing failures of the pipelines. At the same time, gas pipelines usually experience frequent pressure fluctuations, inducing a cyclic loading to cause pipeline fatigue. Nowadays, the role of hydrogen in fatigue cracking has not been fully understood. Sometimes, controversial results are obtained. The hydrogen adsorption/absorption behavior on steels under cyclic loading has rarely been studied.The objective of the proposed international collaboration is to investigate the interaction of hydrogen and fatigue on the structural integrity of steel pipelines in high-pressure hydrogen gas environments, filling knowledge gaps and providing technical recommendations for the safe transport of hydrogen by pipelines. The research will investigate the role of hydrogen in fatigue cracking of pipeline steels, and of the effect of cyclic loading on hydrogen atom permeation and local trapping in the steels under pipeline operating conditions (such as pressure fluctuation amplitude and frequency, temperature, internal pressure, hydrogen/natural gas blending ratio and steel grade). The project will develop an international collaboration in pipeline HE and fatigue research. The outcomes will contribute to accelerated realization of hydrogen economy for global energy transition and decarbonization, placing Canada a leading position in hydrogen pipeline technology in the world.