Synergistic deformation pathways in a TWIP steel at cryogenic temperatures: In situ neutron diffraction
| Autor: | Li Wang, Yu-Lung Chiu, Minshi Wang, Huibin Liu, Biao Cai, Lei Tang, Saurabh Kabra |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
010302 applied physics
Austenite Materials science Polymers and Plastics Twip Metals and Alloys 02 engineering and technology Flow stress 021001 nanoscience & nanotechnology 01 natural sciences Electronic Optical and Magnetic Materials Deformation mechanism Stacking-fault energy 0103 physical sciences Ceramics and Composites Dislocation Deformation (engineering) Composite material 0210 nano-technology Stacking fault |
| Zdroj: | Acta Materialia. 200:943-958 |
| ISSN: | 1359-6454 |
| Popis: | High manganese steels are promising candidates for applications in cryogenic environments. In this study, we investigate the mechanical and microstructural responses of a high manganese twinning induced plasticity (TWIP) steel at a low-temperature range (from 373 to 77 K) via in situ neutron diffraction qualification and correlative microscopy characterization. During plastic deformation, stacking fault probability and dislocation density increased at a faster rate at a lower temperature, hence, higher dislocation density and denser mechanical twins were observed, confirmed by microscopic observation. Stacking fault energy was estimated, dropping linearly from 34.8 mJm−2 at 373 K to 17.2 mJm−2 at 77 K. A small amount of austenite transferred to martensite when deforming at 77 K. The contributions to flow stress from solutes, grain boundary, dislocation, and twinning were determined at different temperatures, which shows that the high work strain hardening capacity of the TWIP steel originates from the synergetic strengthening effects of dislocations and twin-twin networks. These findings reveal the relationship among stacking fault energy, microstructure, and deformation mechanisms at the low-temperature range, paving a way in designing TWIP steels with the superb mechanical performance for cryogenic applications. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect