|About this Abstract
||2022 TMS Annual Meeting & Exhibition
||Environmentally Assisted Cracking: Theory and Practice
||Atomistic Study on Diffusion and Trapping of Hydrogen in Nanocrystalline Steel
||Denver Seely, Bradley Huddleston, Nayeon Lee, Sungkwang Mun, Anh Vo, Doyl Dickel, Krista Limmer
|On-Site Speaker (Planned)
The local equilibrium of hydrogen (H) atoms in polycrystalline steel is analyzed using molecular dynamics (MD) simulations with a Modified Embedded Atom Method potential developed for the Fe-C-H system. MD is a powerful tool to provide information on the nanoscale distribution of H while experimental detection of H is limited. We examine hydrogen diffusion and trapping in a polycrystalline structure of tempered martensitic steel with ~1 million atoms composed of lath sub-grain boundaries, microvoids, solution carbon, and carbides. At 800 K, when hydrogen has higher mobility, hydrogen diffuses toward irregularities of those various trapping sites. The results show that within three ns, approximately 80% of total H are trapped in the vicinity of grain boundaries, and 10% of the atoms reside adjacent to solution carbon and carbides. This work provides comprehensive measures of high local concentrations of hydrogen at grain boundaries that could lead to hydrogen embrittlement fracture.
||Computational Materials Science & Engineering, Iron and Steel, Other