| About this Abstract |
| Meeting |
2021 TMS Annual Meeting & Exhibition
|
| Symposium
|
Phase Transformations and Microstructural Evolution
|
| Presentation Title |
Cementite Formation in Ferritic Steels:Ffirst-principles Based AtomisticSsimulations. |
| Author(s) |
Oceane Buggenhoudt, Chu-Chun Fu, Thomas Schuler, Jean-Luc Béchade |
| On-Site Speaker (Planned) |
Oceane Buggenhoudt |
| Abstract Scope |
Mechanisms of carbon diffusion and agglomeration play a central role in the nucleation process of cementite in α-Fe. However, so far, these properties are poorly known. To address these features, we first identified a precursor of cementite which consists in an ordered structure composed of Fe atoms in quasi-bcc lattice sites and C atoms occupying octahedral sites. Then, we investigated the early stage of cementite nucleation. A set of interaction energies and migration barriers for C interstitials in an α-Fe matrix with different local C concentration are calculated using density functional theory (DFT). Then, we parametrized effective interaction and diffusion models, and performed atomic Monte Carlo simulations. Finally, we studied the diffusion in cementite. We determined the migration barriers of a C interstitial via DFT and the corresponding diffusion coefficients via the computation of transport coefficients. The predicted diffusion coefficients are in good agreement with available experimental data. |
| Proceedings Inclusion? |
Planned: |