Martensite is a body-centered tetragonal form of iron in which some carbon is dissolved. Martensite forms during quenching, when the face centered cubic lattice of austenite is distored into the body centered tetragonal structure without the loss of its contained carbon atoms into cementite and ferrite. Instead, the carbon is retained in the iron crystal structure, which is stretched slightly so that it is no longer cubic. Martensite is more or less ferrite supersaturated with carbon. Compare the grain size in the micrograph with tempered martensite.
|Body Centered Tetragonal Unit Cell||Photomicrograph of Martensite Structure|
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Martensite".
Face Centered Tetragonal image from the Wikipedia article "Crystal structure".
Martensite Photomicrograph Copyright © British Steel; Used with permission, Courtesy of Corus.
Copyright © 2006 Peter L Berglund. (except for Martensite photomicrograph) Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled "GNU Free Documentation License".