Addressing the Hydrogen Embrittlement Challenge in Future Hydrogen Pipelines: A Multiscale Review from Mechanisms to Material Design

To mitigate fossil fuel dependency and facilitate the transition towards a green economy, utilization of hydrogen energy has emerged as a paramount objective. Nevertheless, during transportation, this goal introduces novel challenges pertaining to material integrity, notably hydrogen embrittlement. This review systematically examines contemporary research on hydrogen embrittlement in natural gas pipelines conveying hydrogen blends and elucidates the hydrogen sources, permeation pathways, and embrittlement mechanisms. By scrutinizing the intrinsic material attributes and operational environments, this study provides an in-depth analysis of the pivotal factors influencing the susceptibility of pipeline steel to hydrogen embrittlement, thereby furnishing a theoretical foundation for the enduring safety of hydrogen pipelines.