In-depth Study of Hydrogen Permeation through Steel and Optimization of Palladium Metallization Tatjana Saskia Ott1,2, Elahe Akbari1, Christoph Cobet2, Jiri Duchoslav2, Heiko Groiß2, Laura Louise Elizabeth Mears1, Andreas Muhr3, Reza Sharif3, Thomas Steck3, and Markus Valtiner1 1) Technische Universität Wien, Wien/ Austria 2) Johannes Kepler Universität Linz, Linz/ Austria 3) voestalpine Stahl GmbH, Linz/ Austria Objectives – Hydrogen permeation measurements are a powerful method to gather information about material properties such as diffusion coefficients and trap sites. Additionally, they can be utilized to investigate corrosion processes. By studying the Hydrogen permeation through dual-phase high-strength steel, valuable insights into the mechanisms of cathodic and potentially anodic Hydrogen generation can be obtained. A successful Hydrogen permeation measurement relies on the quality of the Palladium coating. Therefore, the objective of this project is to introduce an optimized method for the Palladium deposition on steel and to demonstrate the range of results achievable through Hydrogen permeation measurements in corrosion research. Results – The electrochemical process for the Palladium deposition on steel was optimized by introducing a reduction step prior to the Palladium deposition. This step ensures that no oxides remain on the substrate, which could otherwise interfere with Hydrogen permeation measurements. The effectiveness of this additional reduction step was confirmed by XPS and TEM analysis, as well as a series of Hydrogen permeation measurements. Following these results, the cathodic Hydrogen production and subsequent Hydrogen permeation was further studied. Finally, the potential for anodic Hydrogen production was investigated. Results demonstrated that Hydrogen permeation measurements can be utilized to measure anodically produced Hydrogen as well. Conclusions – Hydrogen permeation measurements, when combined with optimized sample preparation, have proven to be a powerful tool for obtaining valuable insights into both cathodic and anodic processes leading to Hydrogen formation and subsequent Hydrogen permeation through steel.