|About this Abstract
||2014 TMS Annual Meeting & Exhibition
||Multiscale Approaches to Hydrogen-assisted Degradation of Metals
||Modeling Dislocation Mediated Hydrogen Transport
||Mohsen Dadfarnia, May L Martin, Akihide Nagao, Petros Sofronis, Ian M Robertson
|On-Site Speaker (Planned)
Recent experimental studies of the microstructure beneath fracture surfaces of specimens fractured in hydrogen suggest that the dislocation structure and hydrogen transported by mobile dislocation play important roles in the evolution of the fracture process/event. The experiments indicate that hydrogen is responsible for the copious plasticity in large volumes of material before the onset of fracture. In agreement with previous studies, we stipulate that mobile dislocations transport hydrogen in regions well in front from a crack tip. We propose a revised continuum plasticity model for hydrogen/deformation interactions in order to account for dislocation transport along with stress driven diffusion and trapping at microstructural defects. With the use of this new model, we present numerical simulation results for both transient and steady state hydrogen profiles in the neighborhood of a blunting crack tip. The results are used to make evaluative statements on the mechanism of hydrogen embrittlement.
||Planned: Paper Selections