Impact of Ni alloying on Fe-C martensite ageing: an atomistic investigation

[摘要] We propose a computational investigation of Ni-alloying impact on Fe-C martensite ageing, at the atomic scale. Using the Climbing Image Nudged Elastic Band technique, we showed the repulsive nature of NiC pairwise interactions in alpha-iron, and demonstrated that Ni alloying lowers the migration energies and force dipole tensor components associated to an interstitial carbon in alpha-iron. Computed values of pair wise interactions, migration energies and dipole components were used to implement a Kinetic Monte Carlo approach. We found that Ni alloying: (i) has negligible impact on martensite thermodynamical stability, (ii) accelerates ageing kinetics, by increasing carbon diffusivity. (C) 2021 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

[发布日期] 2021-12-01

[关键词] Martensite ageing;Fe-Ni-C;Carbon diffusion;Climbing Image Nudged Elastic Band;Kinetic Monte-Carlo;Mean-field elastic model