Embrittlement, degradation, and loss prevention of hydrogen pipelines

The detrimental effects induced by hydrogen on different materials—including steels—are a well-known and studied phenomenon. In the last century, several research papers focusing on hydrogen damages were published, including investigations concerning the hydrogen impact on the crack growth rate in steels subjected to cyclic loading. However, the past studies focused on material behavior and the role of external factors (e.g., pressure, temperature, stress field, microstructure, inhibitors, etc.), while the consequences of these findings on safety procedures and guidelines remain unspoken. The present work aims at investigating how the manifestation of the hydrogen degradation effect on equipment subjected to fatigue loadings may reflect on conventional safety practices. More accurately, a review of the parameters governing pipeline fatigue life is undertaken to analyze how such variables may lead to undesirable events and ultimately promoting a loss of containment scenario. In this sense, this work appeals for an evolution of the existing inspection methodologies for components that may experience fatigue failures (i.e., piping and pipeline systems), since the time-dependency of the detrimental effects induced by hydrogen should be considered in the operations of accident prevention and risk mitigation. Hence, the development of a preventive inspection and maintenance strategy specifically conceived for hydrogen technologies is essential to avoid the loss prevention of hydrogen systems. This will not only contribute to a quicker and larger scale spread of a hydrogen infrastructure, but it will also foster the energy-transition challenge that our society is facing today.

Graphical abstract