The high solubility and mobility of hydrogen in metals can cause severe problems for the manufacturing of steels, in particular high strength steels, through hydrogen embrittlement. The microscopic mechanisms of hydrogen embrittlement are manifold and not completely understood. One option for embrittlement in steel is for example the hydrogen induced cracking (HIC), where hydrogen bubbles form in existing voids of the steel and cause a pressure which reduces the ductility and tensile strength of the host steel. Another possible mechanism is the so-called hydrogen attack where the hydrogen impurities react with carbon to form aggregations of methane, resulting in crack events.  

For a quantitative understanding of the processes behind hydrogen embrittlement an un-biased description of thermodynamic as well as kinetic aspects of the hydrogen-metal interaction is essential. We therefore employ Density Functional Theory in the generalized gradient approximation (DFT-GGA) to investigate the Hydrogen-in-Metal Potential Energy Surface (HMPES) for a variety of metals, with a particular focus on steel.  It is planned to determine basic energetic quantities like H-solubilities and diffusion barriers depending on the phase of the host metal, the alloy composite and the adajacent atomic species. Furthermore we plan to deploy our strong background in the ab-initio determination of vibrational properties to account for the important thermodynamic aspects.