| About this Abstract |
| Meeting |
2020 TMS Annual Meeting & Exhibition
|
| Symposium
|
Phase Transformations and Microstructural Evolution
|
| Presentation Title |
Crystallographic Characteristics of γ'-Fe4N Formation Upon Nitriding of α-Fe |
| Author(s) |
Helge Schumann, Gunther Richter, Andreas Leineweber |
| On-Site Speaker (Planned) |
Helge Schumann |
| Abstract Scope |
Nitriding of iron and steel typically generates a nitride compound layer at the surface, leading to improvement of e.g. tribological properties. Especially the transformation of α-Fe to γ'-Fe4N is of interest, because this typically is the first stage of compound layer formation in low-alloy steel and cast iron. In the current study, γ'-Fe4N is generated at the surface of polycrystalline α-Fe plates and single-crystal α-Fe whiskers. In the whiskers quite large γ' plates are formed, with habit planes and orientation relationship to α as predicted requiring an invariant plane strain in combination with a lattice invariant shear already observed previously in Fe4N precipitates developing at low temperatures. In the case of the polycrystalline plates the shear strains associated with γ' cannot be accommodated like within the freestanding whiskers. Instead characteristic variant combinations develop consisting of 6 different orientation variants. Thereby, characteristic orientation variations occur during growth of the γ'. |
| Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |