Abstract
The influence of temperature and stacking fault energy (SFE) on the strain-hardening behavior and critical resolved shear stress for twinning was investigated for three Fe–22/25/28Mn–3Al–3Si wt.% transformation- and twinning-induced plasticity (TRIP/TWIP) steels. The SFEs were calculated by two different methods, density functional theory and statistical thermodynamic modeling. The dislocation structure, observed at low levels of plastic deformation, transitions from “planar” to “wavy” dislocation glide with an increase in temperature, Mn content, and/or SFE. The change in dislocation glide mechanisms from planar to wavy reduces the strain hardening rate, in part due to fewer planar obstacles and greater cross slip activity. In addition, the alloys exhibit a large decrease in strength and ductility with increasing temperature from 25 to 200 °C, attributed to a substantial reduction in the thermally activated component of the flow stress, predominate suppression of TRIP and TWIP, and a significant increase in the critical resolved shear stress for mechanical twinning. Interestingly, the increase in SFE with temperature had a rather minor influence on the critical resolved shear stress for mechanical twinning, and other temperature dependent factors which likely play a more dominant role are discussed.
| Original language | English |
|---|---|
| Article number | 101425 |
| Journal | Materialia |
| Volume | 22 |
| DOIs | |
| State | Published - May 2022 |
Funding
This manuscript has been authored by UT-Battelle, LLC under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan ( http://energy.gov/downloads/doe-public-access-plan ). This work is sponsored by the National Science Foundation Division of Materials Research, USA, under grants DMR0805295 and DMR1309258, by the Ministry of Science and Innovation of Spain, under Grant MAT2012?39124, and under a Center for Nanophase Materials Science user proposal CNMS2014?291 at Oak Ridge National Laboratory. DTP gratefully acknowledges support for extended visits to CSIC, Madrid and MPI, D?sseldorf during his time as a graduate student at Vanderbilt University where most of this research was performed. The authors would also like to acknowledge Easo George and Josh Cicotte for reviewing the manuscript. This work is sponsored by the National Science Foundation Division of Materials Research, USA, under grants DMR0805295 and DMR1309258, by the Ministry of Science and Innovation of Spain, under Grant MAT2012–39124, and under a Center for Nanophase Materials Science user proposal CNMS2014–291 at Oak Ridge National Laboratory. DTP gratefully acknowledges support for extended visits to CSIC, Madrid and MPI, Düsseldorf during his time as a graduate student at Vanderbilt University where most of this research was performed. The authors would also like to acknowledge Easo George and Josh Cicotte for reviewing the manuscript.
| Funders | Funder number |
|---|---|
| Center for Nanophase Materials Science | |
| U.S. Department of Energy | |
| Division of Materials Research | DMR0805295, DMR1309258 |
| Oak Ridge National Laboratory | |
| Vanderbilt University | |
| Ministerio de Ciencia, Innovación y Universidades | MAT2012–39124 |
Keywords
- Plasticity mechanisms
- Stacking fault energy
- TRIP steel
- TWIP steel
- Twinning