Diffusion properties of Fe–C systems studied by using kinetic activation–relaxation technique

Restrepo, Óscar A.; Mousseau, Normand; El-Mellouhi, Fedwa; Bouhali, O.; Trochet, Mickaël; Becquart, Charlotte

doi:10.1016/j.commatsci.2015.10.017

Cited by 25 publications

(17 citation statements)

References 41 publications

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“…Interactions are handled using the Fe-C EAM potential developed by Becquart et al for Fe-C [49,50] and Ackland and Mendelev for Fe-Fe interactions [51]. Both potentials provide an excellent agreement with DFT calculations in bulk Fe [7,50]. K-ART is coupled to LAMMPS library for force and energy calculations [38,39].…”

Section: A K-art Implementationmentioning

confidence: 99%

“…[1][2][3][4][5][6]. These mechanisms have been studied extensively in crystalline bulk [7][8][9][10][11]. C diffusion in grain boundaries (GB), however, has received much less attention [12,13] and relatively little information is available regarding associated C diffusion mechanisms and pathways due, in large part, to the complexity of the environment.…”

Section: Introductionmentioning

confidence: 99%

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Carbon diffusion paths and segregation at high-angle tilt grain boundaries inα-Fe studied by using a kinetic activation-relation technique

et al. 2018

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Carbon diffusion and segregation in iron is fundamental to steel production but is also associated with corrosion. Using the kinetic activation-relaxation technique (k-ART), a kinetic Monte Carlo (KMC) algorithm with an on-the-fly catalog that allows to obtain diffusion properties over large time scales taking into account long-range elastic effects coupled with an EAM force field, we study the motion of a carbon impurity in four Fe systems with high-angle grain boundaries (GB), focusing on the impact of these extended defects on the long-time diffusion of C. Short and long-time stability of the various GBs is first analyzed, which allows us to conclude that the 3(1 1 1)θ = 109.53 • 110 GB is unstable, with Fe migration barriers of ∼0.1 eV or less, and C acts as a pinning center. Focusing on three stable GBs, in all cases, these extended defects trap C in energy states lower than found in the crystal. Yet, contrary to general understanding, we show, through simulations extending to 0.1 s, that even tough C diffusion takes place predominantly in the GB, it is not necessarily faster than in the bulk and can even be slower by one to two orders of magnitude depending on the GB type. Analysis of the energy landscape provided by k-ART also shows that the free cavity volume around the impurity is not a strong predictor of diffusion barrier height. Overall, results show rather complex diffusion kinetics intimately dependent on the local environment.

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Section: A K-art Implementationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Carbon diffusion paths and segregation at high-angle tilt grain boundaries inα-Fe studied by using a kinetic activation-relation technique

et al. 2018

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“…Tapasa et al constructed an Fe─C EAM potential model by combining a Fe EAM with a Fe─C pair function . Restrepo et al constructed an Fe─C EAM model by combining an Fe EAM with an Fe─C EAM . Sak‐Saracino et al constructed hybrid Fe─C potential models by combining an Fe EAM with a C Tersoff potential (authors fitted) and Johnson et al's Fe─C pair function or Rosato's Fe─C pair function .…”

Section: Previously Explored Potentialsmentioning

confidence: 99%

Review and construction of interatomic potentials for molecular dynamics studies of hydrogen embrittlement in Fe─C based steels

et al. 2020

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Reducing hydrogen embrittlement in the low‐cost Fe─C based steels have the potential to significantly impact the development of hydrogen energy technologies. Molecular dynamics studies of hydrogen interactions with Fe─C steels provide fundamental information about the behavior of hydrogen at microstructural length scales, although such studies have not been performed due to the lack of an Fe─C─H ternary interatomic potential. In this work, the literature on interatomic potentials related to the Fe─C─H systems are reviewed with the aim of constructing an Fe─C─H potential from the published binary potentials. We found that Fe─C, Fe─H, and C─H bond order potentials exist and can be combined to construct an Fe─C─H ternary potential. Therefore, we constructed two such Fe─C─H potentials and demonstrate that these ternary potentials can reasonably capture hydrogen effects on deformation characteristics and deformation mechanisms for a variety of microstructural variations of the Fe─C steels, including martensite that results from γ to α phase transformation, and pearlite that results from the eutectic formation of the Fe3C cementite compound.

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“…The parameter set was then modified to make the potential landscape around the saddle point more realistic . This Fe–C potential has been widely used to model Fe–C systems, with a particular focus on carbon‐dislocation interactions and the dynamics of carbon in bulk Fe . It was also used to model internal friction experiments , martensite properties , and C ordering in Fe–C crystallites at high C concentrations .…”

Section: Introductionmentioning

confidence: 99%

Carbon adsorption on and diffusion through the Fe(110) surface and in bulk: Developing a new strategy for the use of empirical potentials in complex material set‐ups

Sahputra

Chakrabarty

Restrepo

et al. 2016

Physica Status Solidi (b)

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Oil and gas infrastructures are submitted to extreme conditions and off‐shore rigs and petrochemical installations require expensive high‐quality materials to limit damaging failures. Yet, due to a lack of microscopic understanding, most of these materials are developed and selected based on empirical evidence leading to over‐qualified infrastructures. Computational efforts are necessary, therefore, to identify the link between atomistic and macroscopic scales and support the development of better targeted materials for this and other energy industry. As a first step towards understanding carburization and metal dusting, we assess the capabilities of an embedded atom method (EAM) empirical force field as well as those of a ReaxFF force field using two different parameter sets to describe carbon diffusion at the surface of Fe, comparing the adsorption and diffusion of carbon into the 110 surface and in bulk of α‐iron with equivalent results produced by density functional theory (DFT). The EAM potential has been previously used successfully for bulk Fe–C systems. Our study indicates that preference for C adsorption site, the surface to subsurface diffusion of C atoms and their migration paths over the 110 surface are in good agreement with DFT. The ReaxFF potential is more suited for simulating the hydrocarbon reaction at the surface while the subsequent diffusion to subsurface and bulk is better captured with the EAM potential. This result opens the door to a new approach for using empirical potentials in the study of complex material set‐ups.

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Diffusion properties of Fe–C systems studied by using kinetic activation–relaxation technique

Cited by 25 publications

References 41 publications

Carbon diffusion paths and segregation at high-angle tilt grain boundaries inα-Fe studied by using a kinetic activation-relation technique

Carbon diffusion paths and segregation at high-angle tilt grain boundaries inα-Fe studied by using a kinetic activation-relation technique

Review and construction of interatomic potentials for molecular dynamics studies of hydrogen embrittlement in Fe─C based steels

Carbon adsorption on and diffusion through the Fe(110) surface and in bulk: Developing a new strategy for the use of empirical potentials in complex material set‐ups

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