Jump to main content
Jump to site search
SCHEDULED MAINTENANCE Close the message box

Maintenance work is planned for Monday 16 August 2021 from 07:00 to 23:59 (BST).

Website performance may be temporarily affected and you may not be able to access some PDFs or images. If this does happen, refreshing your web browser should resolve the issue. We apologise for any inconvenience this might cause and thank you for your patience.


Issue 2, 2016

Interactions of hydrogen with the iron and iron carbide interfaces: a ReaxFF molecular dynamics study

Author affiliations

Abstract

Hydrogen embrittlement (HE) is a well-known material phenomenon that causes significant loss in the mechanical strength of structural iron and often leads to catastrophic failures. In order to provide a detailed atomistic description of HE we have used a reactive bond order potential to adequately describe the diffusion of hydrogen as well as its chemical interaction with other hydrogen atoms, defects, and the host metal. The currently published ReaxFF force field for Fe/C/H systems was originally developed to describe Fischer–Tropsch (FT) catalysis [C. Zou, A. C. T. van Duin and D. C. Sorescu, Top. Catal., 2012, 55, 391–401], and especially had been trained for surface formation energies, binding energies of small hydrocarbon radicals on different surfaces of iron and the barrier heights of surface reactions. We merged this force field with the latest ReaxFF carbon parameters [S. Goverapet Srinivasan, A. C. T. van Duin and P. Ganesh, J. Phys. Chem. A, 2015, 119, 1089–5639] and used the same training data set to refit the Fe/C interaction parameters. The present work is focused on evaluating the applicability of this reactive force field to describe material characteristics and study the role of defects and impurities in the bulk and at the precipitator interfaces. We study the interactions of hydrogen with pure and defective α-iron (ferrite), Fe3C (cementite), and ferrite–cementite interfaces with a vacancy cluster. We also investigate the growth of nanovoids in α-iron using a grand canonical Monte Carlo (GCMC) scheme. The calculated hydrogen diffusion coefficients for both ferrite and cementite phases predict a decrease in the work of separation with increasing hydrogen concentration at the ferrite–cementite interface, suggesting a hydrogen-induced decohesion behavior. Hydrogen accumulation at the interface was observed during molecular dynamics (MD) simulations, which is consistent with experimental findings. These results demonstrate the ability of the ReaxFF potential to elucidate various aspects of hydrogen embrittlement in α-iron and hydrogen interactions at a more complex metal/metal carbide interface.

Graphical abstract: Interactions of hydrogen with the iron and iron carbide interfaces: a ReaxFF molecular dynamics study

Supplementary files

Article information


Submitted
10 Oct 2015
Accepted
18 Nov 2015
First published
18 Nov 2015

Phys. Chem. Chem. Phys., 2016,18, 761-771
Article type
Paper
Author version available

Interactions of hydrogen with the iron and iron carbide interfaces: a ReaxFF molecular dynamics study

M. M. Islam, C. Zou, A. C. T. van Duin and S. Raman, Phys. Chem. Chem. Phys., 2016, 18, 761 DOI: 10.1039/C5CP06108C

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.


Social activity

Search articles by author

Spotlight

Advertisements