|About this Abstract
||2014 TMS Annual Meeting & Exhibition
||Multiscale Approaches to Hydrogen-assisted Degradation of Metals
||Modeling of Gaseous Impurity Inhibition of Hydrogen Environment Embrittlement
||Brian Somerday, Alex Staykov, Petros Sofronis, Reiner Kirchheim
|On-Site Speaker (Planned)
Although gaseous impurity inhibition of hydrogen environment embrittlement has been recognized, establishing a comprehensive understanding of the phenomenon is challenging since the mechanisms operate at the atomic scale. The activities reviewed here focus on applying analytical and numerical models to gain insights into the variables and mechanisms governing oxygen inhibition of gaseous hydrogen embrittlement of structural metals. Density functional theory (DFT) modeling reveals how 1) part-per-million levels of oxygen can compete with hydrogen for surface adsorption sites, and 2) dissociated oxygen on the surface suppresses the catalytic activity of the metal towards hydrogen dissociation. In addition, an idealized analytical crack-tip model demonstrates that inhibition is rate-limited by oxygen diffusion through the hydrogen gas-filled crack channel. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.
||Planned: Paper Selections