Journal
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
Volume 700, Issue -, Pages 250-258Publisher
ELSEVIER SCIENCE SA
DOI: 10.1016/j.msea.2017.06.012
Keywords
TWIP steel; Dynamic strain aging; Work hardening; Serrated flow; Local strain rate
Categories
Funding
- National Natural Science Foundation of China [51604021]
- China Postdoctoral Science Foundation [2016M591077]
- Beijing Natural Science Foundation [2174077]
- Fundamental Research Funds for the Central Universities [FRF-TP-15-066A1]
Ask authors/readers for more resources
The twinning and dynamic strain aging(DSA) induced work hardening in Fe-Mn-C TWIP steel has been experimentally investigated in view of grain morphology, stress strain response, local strain rate(LSR) and strain hardening rate. A strain of 0.3 should be the critical value for the saturation of twined grains in Fe-Mn-C TWIP steel with 0.4-0.6 wt% carbon and 18-22 wt% manganese. DSA can occur in the very beginning of plastic deformation in Fe-Mn-C TWIP steel with the unpronounced fluctuation in stress strain response but obvious discontinuity in work hardening and LSR. The mechanism on strain hardening of Fe-Mn-C TWIP steel during tensile deformation can be distinguished by the variation of LSR. Twinning induced hardening rate is around 3.0 GPa with a steady LSR, while DSA induced hardening rate is about 2.0 GPa with a periodic and unstable fluctuation of LSR. There are mainly three stages in the work hardening of Fe-Mn-C TWIP steel divided by the inducing mechanism: twinning dominant, twinning+DSA dominant and DSA dominant. A strong correlation between the fluctuating characteristic of LSR and work hardening rate has been observed. In twinning dominant stage, they are largely steady; while in the other two stages, more significant fluctuation is observed where DSA is more pronounced for both curves. The serration in stress corresponds to the plateau in strain and low LSR, as well as the peak of strain hardening rate, due to the occurrence of DSA; and the smooth stress evolution between two serrations correlates the apparent increase of strain, and high LSR, together with the trough of strain hardening rate, relating to the preparation time for next DSA.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available