About this Abstract |
| Meeting |
2026 TMS Annual Meeting & Exhibition
|
| Symposium
|
Fatigue in Materials: Fundamentals, Multiscale Characterizations and Computational Modeling
|
| Presentation Title |
Influence of Formation of Fine Dislocation Sub-Cells on Fatigue Strength and Crack Initiation |
| Author(s) |
Guocai Chai, Jens Bergstrom, Mattias Calmunger |
| On-Site Speaker (Planned) |
Guocai Chai |
| Abstract Scope |
Dislocation sub-cells are commonly formed in metallic materials as a result of the dislocation interactions during cyclic loading. The density and size of the sub-cells are crucial to affect the fatigue behavior. In this study, the influence of formation of fine dislocation sub-cells on the fatigue behaviors in two austenitic stainless steels has been discussed. Intensive nano dislocation sub-cells were introduced by pulsating stepwise cyclic loadings up to a range of >10^8 cycles/step. The fatigue strengths of the alloys increased about two times and the fatigue lives increased from about 2x10^6 cycle to 10^9 cycles, almost 1000 times. Another phenomenon is that the formation of intensive fine dislocation sub-cells can lead to a transition of fatigue crack initiation from the material surface to the subsurface with a fine granular area in the matrix without defect. This work shows that formation of fine dislocation sub-cells can greatly improve resistance to fatigue. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Mechanical Properties, Iron and Steel, Characterization |