A Review on Hydrogen Embrittlement and Risk-based Inspection of Hydrogen Technologies

Hydrogen could gradually replace fossil fuels, mitigating the human impact on the environment. However, equipment exposed to hydrogen is subjected to damaging effects due to H2 absorption and permeation through metals. Hence, inspection activities are necessary to preserve the physical integrity of the containment systems, and the risk-based (RBI) methodology is considered the most beneficial approach. This review aims to provide relevant information regarding hydrogen embrittlement, its effect on materials’ properties, and the synergistic interplay of the factors influencing its occurrence. Moreover, an overview of predictive maintenance strategies is presented, focusing on the RBI methodology. A systematic review was carried out to identify examples of the application of RBI to equipment exposed to hydrogenated environments and to identify the most active research groups. In conclusion, a significant lack of knowledge has been highlighted, along with difficulties in applying the RBI methodology for equipment operating in a pure hydrogen environment.