Cementite

Description

A hard, brittle material composed of iron carbide. Cementite is present in nearly all iron-carbon alloys, such as steel and iron cast iron. It is a metastable phase that will decompose to form graphite and iron. Although in steel, this decomposition rarely occurs. Most cast irons contain some free graphite because the silicon content of cast iron makes cementite less stable.

Synonyms and Related Terms

iron carbide; cohenite; elezo (Ces.); Zementit (Deut.); cmenite (Fr.); cementiet (Ned.); cementyt (Pol.); cementite (Port.)

Other Properties

Orthorhombic crystal system

Composition	F3C

Authority

• G.S.Brady, G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p. 156

• Richard S. Lewis, Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993

• David C. Scott, David C. Scott, Metallography and Microstructure of Ancient and Historic Metals, The Getty Conservation Institute, Los Angeles, 1991

• Wikipedia, the free encyclopedia, at http://www.wikipedia.com Comment: http://en.wikipedia.org/wiki/Iron_carbide (Accessed Mar. 1, 2006)

• Random House, Random House, Webster's Encyclopedic Unabridged Dictionary of the English Language, Grammercy Book, New York, 1997

• The American Heritage Dictionary or Encarta, via Microsoft Bookshelf 98, Microsoft Corp., 1998