About this Abstract |
| Meeting |
2027 TMS Annual Meeting & Exhibition
|
| Symposium
|
Fundamentals of Sustainable Metallurgy and Materials Science
|
| Presentation Title |
Green ironmaking under high H2 pressure: Resolving individual reaction steps via in-situ synchrotron high-energy X-ray diffraction |
| Author(s) |
Özge Özgün, Kartik Umate, Gökhan Gizer , Laurine Choisez, Eric Woods, Guillermo Requena, Claudio Pistidda , Dierk Raabe , Yan Ma |
| On-Site Speaker (Planned) |
Özge Özgün |
| Abstract Scope |
Hydrogen-based direct reduction (HyDR) of hematite is a promising route for steel decarbonization. HyDR involves the sequential reduction of hematite to magnetite, wüstite, and metallic iron above 570 °C, with wüstite-to-iron reduction as the rate-limiting step. Although overall reduction kinetics are strongly influenced by H2 pressure, its effect on the individual reaction steps remains unclear. Here, we used in-situ synchrotron high-energy XRD to monitor phase transformations during hematite reduction at 700 °C under H2 pressures from 1 to 100 bar. Higher H2 pressure accelerated all reduction steps and lowered their onset temperatures. Wüstite-to-iron reduction remained phase-boundary controlled, while increasing H2 pressure enhanced interface velocity and accelerated the reaction. Pore morphology evolved from elongated to equiaxed with increasing H2 pressure, accompanied by reduced pore connectivity, indicating a shift in balance between void formation and interface mobility. These findings provide insights into the role of H2 pressure in HyDR and reactor optimization. |
| Proceedings Inclusion? |
Undecided |
| Keywords |
Sustainability, Iron and Steel, Phase Transformations |