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Abstract

The term "hydrogen embrittlement" (HE) refers to a variety of events involving the negative effects of hydrogen in metallic materials. Reducing hydrogen diffusion within microstructures is the most effective way to mitigate HE. This requires a thorough understanding of the impact of local heterogeneities at different length scales. Although advanced experimental and computational methods exist for this purpose, they are typically applied to samples or models of varying complexity, making it challenging to compare and combine results. In this study, a ferritic Fe-based alloy with reduced chemical complexity is produced on a laboratory scale and subjected to various thermomechanical treatments. EBSD is used to analyse the microstructure, including determination of CSL grain boundary characteristics. At the same time, ab initio density functional theory calculations are used to calculate the hydrogen trapping energies and diffusion barriers under different local chemistry conditions and different CSL boundaries. The simulation results will be used to determine the hydrogen storage capacity of the local heterogeneities and their effect on the hydrogen diffusion coefficient in the experimental microstructures. In the later stage of this project, the predictions shall be supported by experiments. This contribution demonstrates the potential and challenges for combining simulation and experimental methods, to better understand how heterogeneities affect hydrogen behaviour in different iron and steel microstructures.