TY - JOUR
T1 - Effect of C on the martensitic transformation in Fe-C alloys in the presence of pre-existing defects
T2 - A molecular dynamics study
AU - Karewar, Shivraj
AU - Sietsma, Jilt
AU - Santofimia Navarro, Maria
PY - 2019
Y1 - 2019
N2 - Molecular dynamics simulations are used to investigate the atomic effects of carbon (C) addition in Fe on the martensitic phase transformation in the presence of pre-existing defects such as stacking faults and twin boundaries. The pre-existing defect structures in Fe-C alloys have the same effect on the atomistic mechanisms of martensitic transformation as in pure Fe. However, C addition decreases the martensitic transformation temperature. This effect is captured by characterizing three parameters at the atomic level: atomic shear stresses, atomic energy, and total energy as a function of temperature for face-centered-cubic (fcc) and body-centered-cubic (bcc) phases. The thermodynamic effect of fcc phase stabilization by C addition is revealed by the atomic energy at a particular temperature and total energy as a function of temperature. The barrier for fcc-to-bcc transformation is revealed by analysis of atomic shear stresses. The analysis indicates that addition of C increases the atomic shear stresses for atomic displacements during martensitic transformation, which in turn decreases the martensitic transformation temperature.
AB - Molecular dynamics simulations are used to investigate the atomic effects of carbon (C) addition in Fe on the martensitic phase transformation in the presence of pre-existing defects such as stacking faults and twin boundaries. The pre-existing defect structures in Fe-C alloys have the same effect on the atomistic mechanisms of martensitic transformation as in pure Fe. However, C addition decreases the martensitic transformation temperature. This effect is captured by characterizing three parameters at the atomic level: atomic shear stresses, atomic energy, and total energy as a function of temperature for face-centered-cubic (fcc) and body-centered-cubic (bcc) phases. The thermodynamic effect of fcc phase stabilization by C addition is revealed by the atomic energy at a particular temperature and total energy as a function of temperature. The barrier for fcc-to-bcc transformation is revealed by analysis of atomic shear stresses. The analysis indicates that addition of C increases the atomic shear stresses for atomic displacements during martensitic transformation, which in turn decreases the martensitic transformation temperature.
KW - Fe-C alloys
KW - Martensitic transformations
KW - Molecular dynamics
KW - Stacking faults
KW - Twin boundary
UR - http://www.scopus.com/inward/record.url?scp=85062876387&partnerID=8YFLogxK
U2 - 10.3390/cryst9020099
DO - 10.3390/cryst9020099
M3 - Article
AN - SCOPUS:85062876387
SN - 2073-4352
VL - 9
JO - Crystals
JF - Crystals
IS - 2
M1 - 99
ER -