Abstract
The transition to hydrogen-based energy systems introduces significant challenges, with hydrogen embrittlement (HE) in steel components being a major concern in repurposing natural gas infrastructure. A thorough understanding of the factors that influence hydrogen entry and embrittlement is crucial to mitigating this risk. Although considerable research has focused on environmental conditions and material properties, the role of surface state, including oxides, corrosion products (CPs), and contaminants from field exposure, remains underexplored. This work investigates the effect of surface state on hydrogen uptake, diffusivity and embrittlement of L360 steel using thermal desorption analysis, electrochemical permeation test, and slow strain rate test. It has been revealed that only the presence of brine promotes hydrogen uptake into the steel in gaseous hydrogen environment. The presence of CP layers leads to inhibition of hydrogen uptake and HE implying that the CP scales can be employed as hydrogen barriers in gaseous hydrogen environments.