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TY - THES AU - Tekkaya, Berk TI - A multi-scale framework to characterize hydrogen-induced damage in steels PB - Rheinisch-Westfälische Technische Hochschule Aachen VL - Dissertation CY - Aachen M1 - RWTH-2025-06524 SP - 1 Online-Ressource : Illustrationen PY - 2025 N1 - Veröffentlicht auf dem Publikationsserver der RWTH Aachen University 2026 N1 - Dissertation, Rheinisch-Westfälische Technische Hochschule Aachen, 2025 AB - As an energy carrier, hydrogen can ensure a sustainable energy supply in the future. However, an infrastructure for the safe transportation and storage of hydrogen-containing media must be established and the repurposing of existing natural gas pipelines for hydrogen transportation (=European Hydrogen Backbone) must be investigated with regard to material’s integrity. Since hydrogen has an embrittling effect on the material properties of steels and leads to failure due to hydrogen-induced cracking under the impact of stresses, this is a highly challenging task, both scientifically and economically. With the objective of characterizing the hydrogen resistance of steels, a numerical framework is developed on different scales, which are coupled with each other. On the microscale, this modeling approach enables the investigation of the microstructural properties on hydrogen diffusion and trapping behavior using the implemented coupled crystal plasticity model with hydrogen transport. On the mesoscale, the influence of hydrogen on the damage behavior can be analyzed, taking into account the stress state, by simulating the most common laboratory tests for determining the material properties with and without hydrogen loading. A coupled chemical-mechanical damage model is implemented for this purpose. On the macroscale, the influence of the loading history from cold forming on the material's susceptibility to hydrogen is investigated. The UOE pipe forming process is considered for the production of the pipes. The submodeling approach is used to place microstructural models (sRVE) at different locations in the pipe, which pass through the individual forming steps. With a subsequent application of the hydrogen concentration and the simulation of hydrogen diffusion, the hydrogen concentrations in the microstructure are computed. In this way, critical points in the pipe for hydrogen-induced crack formation are determined based on the microstructural characteristics. Furthermore, this multi-scale approach provides the simulation of the so-called HIC test under the influence of residual stresses for a specimen taken from a pipe, for example. The implemented material models were calibrated and validated using experimental data. LB - PUB:(DE-HGF)11 DO - DOI:10.18154/RWTH-2025-06524 UR - https://publications.rwth-aachen.de/record/1015683 ER -