|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||Advanced High-strength Steels
||Ab Initio Insights into Hydrogen Trapping by Precipitates in High-strength Steels
||Tilmann Hickel, Eunan McEniry, Poulumi Dey, Joerg Neugebauer; Tilmann Hickel, Eunan McEniry, Poulumi Dey, Joerg Neugebauer
|On-Site Speaker (Planned)
||Tilmann Hickel; Tilmann Hickel
We use first principles methods to simulate the interaction of hydrogen with precipitates in advanced high-strength steels. To understand the impact of chemical and mechanical contributions to H solution enthalpies in the interfaces, the role of iron-based and titanium-based precipitates are compared. For perfect and coherent interfaces the trapping energies are generally found to be small, but a noticeable impact on decohesion energies is confirmed. The presence of vacancies in the interface substantially increases the hydrogen trapping.
In the same way, the impact of misfit dislocations on H solubility is considered in a semi-coherent approach. Different concepts to calculate the role of misfit dislocations are presented, using density functional theory as well as tight-binding approaches. We compare the results obtained for precipitates with the H trapping at edge dislocations and grain boundaries. The insights can contribute to an optimization of microstructures such that their sensitivity to hydrogen embrittlement is reduced.
||Planned: Supplemental Proceedings volume