Table of Contents
ISRN Metallurgy
Volume 2012, Article ID 732471, 16 pages
Review Article

Overview of Intermetallic Sigma ( 𝜎 ) Phase Precipitation in Stainless Steels

Department of Materials Science and Engineering, National Chung Hsing University, 250 Kuo-Kuang Road, Taichung 402, Taiwan

Received 14 December 2011; Accepted 19 January 2012

Academic Editors: M. Gjoka and Y. Yamabe-Mitarai

Copyright Β© 2012 Chih-Chun Hsieh and Weite Wu. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The 𝜎 phase which exists in various series of stainless steels is a significant subject in steels science and engineering. The precipitation of the 𝜎 phase is also a widely discussed aspect of the science and technology of stainless steels. The microstructural variation, precipitation mechanism, prediction method, and effects of properties of 𝜎 phase are also of importance in academic discussions. In the first section, a brief introduction to the development and the precipitation characteristics (including morphologies and precipitation sites) of 𝜎 phase in stainless steels is presented. In the second section, the properties effect, prediction method, processing effect, elemental addition, retardation method and Thermo-Calc simulation of the 𝜎 phase in stainless steels are highlighted.