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

• Published in: Scripta Materialia Vol. 205; p. 114182
• Main Authors: Eyméoud, Paul, Huang, Liangzhao, Maugis, Philippe
• Format: Journal Article Paper
• Language: English
• Published: Elsevier Ltd 01.12.2021; Elsevier
• Subjects: Carbon diffusion; Chemical Sciences; Climbing Image Nudged Elastic Band; Fe-Ni-C; Kinetic Monte-Carlo; Martensite ageing; Material chemistry; Mean-field elastic model; Martensite ageing; Fe-Ni-C; Climbing Image Nudged Elastic Band; Mean-field elastic model; Kinetic Monte-Carlo; Carbon diffusion; Mean-field elastic mode
• ISSN: 1359-6462; 1872-8456
• DOI: 10.1016/j.scriptamat.2021.114182

•Computational investigation combining first-principles and Kinetic Monte-Carlo approaches.•Ni alloying lowers migration energies and force dipole tensor components associated to an interstitial C in α-Fe.•Ni alloying accelerates ageing kinetics. [Display omitted] 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 Ni-C pairwise interactions in α-iron, and demonstrated that Ni alloying lowers the migration energies and force dipole tensor components associated to an interstitial carbon in α-iron. Computed values of pairwise 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.