First Principles Calculation of Hydrogen Embrittlement in Iron

Article Preview

Abstract:

Hydrogen embrittlement in iron and steels has been studied for long years. Although a few mechanisms of it have been proposed, it has not been clearly understood yet. Especially, the decohesion theory and the hydrogen enhanced localized plasticity theory have been discussed in the center of attention. Hydrogen is considered to induce a cleavage fracture in the former, but enhance slips in the latter. It is essential problem which hydrogen induces cleavage or slip in hydrogen embrittlement. The purpose of the present paper is to clarify the effects of hydrogen in iron single crystal on the fracture or deformation using first principles calculation. In the cleavage model, the changes of total energy were estimated with a distance of a pair of {001} planes in a unit cell composed of 12 iron atoms and a hydrogen atom. In the slip model, the changes of total energy were estimated with a displacement of a few {110} layers toward <111> direction. Hydrogen reduces the total energy in the cleavage model, but does not change that in the slip model.

You might also be interested in these eBooks

Info:

Periodical:

Key Engineering Materials (Volumes 417-418)

Pages:

285-288

Citation:

Online since:

October 2009

Authors:

Export:

Price:

Permissions CCC:

Permissions PLS:

Сopyright:

© 2010 Trans Tech Publications Ltd. All Rights Reserved

Share:

Citation:

[1] A.R. Triano: Trans ASM Vol. 52 (1960) , p.54.

Google Scholar

[2] C.D. Beachem: Metall. Trans. Vol. 3 (1972) p.437.

Google Scholar

[3] F. Terasaki, T. Kawakami, A. Yoshikawa and N. Takano: La Revue de Metall. Vol. 95 (1998) p.1519.

Google Scholar

[4] D.E. Jiang and E.A. Carter: Acta Mater. Vol. 52 (2004) p.4801.

Google Scholar

[5] P. Blaha,K. Schwarz and J. Luitz: WIE�97, A Full Potential Linearized Augmented Plane Wave Package for Calculating Crystal Properties (Karlheinz Schwarz, Techn. Univ. Wien, Austria, 1999) ISBN 3-9501031-0-4.

Google Scholar

[6] J.P. Perdew,K. Burke and M. Ernzerhof: Phys. Rev. Lett. Vol. 77 (1996) p.3865.

Google Scholar

[7] S.P. Lynch: Acta Metall. Vol. 36 (1988) p.2639.

Google Scholar