About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
|
Fundamentals of Sustainable Metallurgy and Processing of Materials
|
| Presentation Title |
Fundamental Mechanisms in Hydrogen-Based Direct Reduction of Metal Oxides |
| Author(s) |
Dierk R. Raabe, Shaolou Wei |
| On-Site Speaker (Planned) |
Dierk R. Raabe |
| Abstract Scope |
The transition to hydrogen-based direct reduction (HyDR) of metal oxides represents a paradigm shift in metallurgy. Recent advances have elucidated the complex interplay between thermodynamics, kinetics, and microstructure evolution during HyDR, particularly for iron oxides. Key findings reveal that reduction proceeds via multi-step pathways (e.g., Fe₂O₃ → Fe₃O₄ → FeO → Fe), with the wüstite (FeO)-to-iron step emerging as the rate-limiting stage due to sluggish oxygen diffusion through dense iron layers. Atomic-scale experimental and theoretical studies highlight the role of microstructure in mass transport and transformation kinetics and reveal the effects of transient oxide phases that can impede reduction kinetics, while lattice defects such as dislocations and cracks enhance mass transport. These insights were used to develop a novel "one-step from oxides-to-alloy" co-reduction approach to further demonstrate the potential to merge extraction, alloying, and densification into a single solid-state operation, as exemplified by the synthesis of Fe-Ni invar alloys. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Extraction and Processing, Phase Transformations, Iron and Steel |