| About this Abstract |
| Meeting |
2025 TMS Annual Meeting & Exhibition
|
| Symposium
|
Steels in Extreme Environments
|
| Presentation Title |
Superior fatigue resistance of ultrafine bainitic steel by exploiting segregation-induced bands |
| Author(s) |
Bright Mweene, Sumit Ghosh, Mahesh Somani, Ankur Chauhan |
| On-Site Speaker (Planned) |
Ankur Chauhan |
| Abstract Scope |
An ultrafine bainitic steel with segregation-induced martensitic/austenitic (MA) bands was designed. It has a room temperature yield strength of ~914 MPa, ultimate tensile strength of ~1969 MPa, and ~11.5% total elongation. Low cycle fatigue (LCF) behavior was studied under fully reversed strain-controlled conditions at RT, with the loading axis parallel to the MA bands. The LCF stress response showed initial cyclic hardening followed by softening or saturation, attributed to RA transforming to martensite, dislocation interactions, and the softening effects of dislocation annihilation and crack propagation. Damage studies revealed mixed fracture modes, including brittle striations, secondary cracks, quasi-cleavage facets, and dimples. Secondary cracks mainly propagated along matrix-bands interphase regions or within MA bands. Surface-initiated cracks were deflected around interphase regions, increasing tortuosity and reducing the crack propagation rate. This steel’s work hardening and banded microstructure contribute to superior fatigue resistance compared to non-banded bainitic steels. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Iron and Steel, Mechanical Properties, Characterization |