From the perspective of new technology of blending hydrogen into natural gas pipelines transmission: Mechanism, experimental study, and suggestions for further work of hydrogen embrittlement in high-strength pipeline steels

Blending hydrogen into high-strength pipeline steels for high-pressure transmission may cause materials' hydrogen embrittlement (HE) failure. Although the hydrogen-induced failure of metallic materials has been studied for a long time, the process of hydrogen into the materials, hydrogen-induced delayed failure, and dynamic mechanisms of high-strength pipeline steels under high pressure have not been fully understood. This paper aims to provide a detailed review of the latest research on the hydrogen-induced failure of high-strength pipeline steels in hydrogen-blended natural gas transmission. First, introduced the typical hydrogen blending natural gas pipeline transmission projects and their associated research conclusions. Then, described the physical process of the HE in high-strength pipeline steels and the principle, development, and latest research progress of typical hydrogen embrittlement mechanisms in detail. Third, reviewed the research methods and progress of experimental and theoretical simulations for the HE in steels, including hydrogen permeation (HP) experiments, hydrogen content measurements, hydrogen distribution detection, mechanical property tests, and molecular dynamics simulations. The shortcomings of existing experimental and theoretical simulation methods in the hydrogen-induced analysis of high-strength natural gas pipeline steels under high pressure are discussed. Finally, the future research directions and challenges of this problem are proposed from three aspects: the multimechanism synergy mechanism, the improvement of experimental methods, and the establishment of a new interatomic multiscale model.