A1 Refereed original research article in a scientific journal
Stacking fault energy of C-alloyed steels: The effect of magnetism
Authors: Lu S, Li RH, Kadas K, Zhang HL, Tian YZ, Kwon SK, Kokko K, Hu QM, Hertzman S, Vitos L
Publisher: PERGAMON-ELSEVIER SCIENCE LTD
Publication year: 2017
Journal: Acta Materialia
Journal name in source: ACTA MATERIALIA
Journal acronym: ACTA MATER
Volume: 122
First page : 72
Last page: 81
Number of pages: 10
ISSN: 1359-6454
eISSN: 1873-2453
DOI: https://doi.org/10.1016/j.actamat.2016.09.038
Abstract
First-principles calculations have been performed to study the effect of C on the stacking fault energy (SFE) of paramagnetic gamma-Fe and Fe-Cr-Ni austenitic steel. In these systems, the local magnetic structure is very sensitive to the volume in both fcc and hcp structures, which emphasizes the importance of the magnetovolume coupling effect on the SFE. The presence of C atom suppresses the local magnetic moments of Fe atoms in the first coordination shell of C. Compared to the hypothetical nonmagnetic case, paramagnetism significantly reduces the effect of C on the SFE. In the scenario of C being depleted from the stacking fault structure or twin boundaries, e.g., due to elevated temperature, where the chemical effect of C is dissipated, we calculate the C-induced volume expansion effect on the SFE. The volume induced change in the SFE corresponds to more than 50% of the total C effect on the SFE obtained assuming uniform C distribution. (C) 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
First-principles calculations have been performed to study the effect of C on the stacking fault energy (SFE) of paramagnetic gamma-Fe and Fe-Cr-Ni austenitic steel. In these systems, the local magnetic structure is very sensitive to the volume in both fcc and hcp structures, which emphasizes the importance of the magnetovolume coupling effect on the SFE. The presence of C atom suppresses the local magnetic moments of Fe atoms in the first coordination shell of C. Compared to the hypothetical nonmagnetic case, paramagnetism significantly reduces the effect of C on the SFE. In the scenario of C being depleted from the stacking fault structure or twin boundaries, e.g., due to elevated temperature, where the chemical effect of C is dissipated, we calculate the C-induced volume expansion effect on the SFE. The volume induced change in the SFE corresponds to more than 50% of the total C effect on the SFE obtained assuming uniform C distribution. (C) 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
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