The influence of temperature on the strain-hardening behavior of Fe-22/25/28Mn-3Al-3Si TRIP/TWIP steels

Autor: D.T. Pierce, J.T. Benzing, J.A. Jiménez, T. Hickel, I. Bleskov, J. Keum, D. Raabe, J.E. Wittig
Přispěvatelé: National Science Foundation (US), Ministerio de Ciencia e Innovación (España), Oak Ridge National Laboratory (US)
Rok vydání: 2022
Předmět:
Zdroj: Materialia. 22:101425
ISSN: 2589-1529
DOI: 10.1016/j.mtla.2022.101425
Popis: 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.
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.
Databáze: OpenAIRE
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