Cementite

cementite

[si′men‚tīt]

(metallurgy)

Fe₃C A hard, brittle, crystalline compound occurring as lamellae or plates in steel. Also known as iron carbide.

McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Cementite

 

an iron carbide, Fe₃C; a phase and structural component of iron-carbon alloys (seeIRON-CARBON ALLOYS). Cementite has an orthorhombic crystal lattice. It is very hard and brittle and is slightly magnetic at temperatures up to 210°C. It is a metastable phase; the formation of the stable phase—graphite—is in many cases difficult. Cementite is precipitated from a melt consisting of austenite and ferrite. Depending on the crystallization conditions and subsequent treatment, it can have various forms, such as equiaxial grains, lattices along grain boundaries, and plates; it can also exhibit a Widmannstatten structure. Cementite is a constituent of the structural components of steel and cast iron—ledeburite, pearlite, bainite, and tempered sorbite.

REFERENCE

Bunin, K. P., and A. A. Baranov. Metallografiia. Moscow, 1970.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.