Cementite

Cementite

Cementite or iron carbide is a chemical compound with the formula Fe3C (or Fe2C:Fe), and an orthorhombic crystal structure. It is a hard, brittle material, normally classified as a ceramic in its pure form, though it is more important in metallurgy.

It forms directly from the melt in the case of white cast iron. In carbon steel, it either forms from austenite during cooling or from martensite during tempering. It mixes with ferrite, the other product of austenite, to form lamellar structures called pearlite and bainite. Much larger lamellae, visible to the naked eye, make up the structure of Damascus steel, though the process has been lost to history.

Fe3C is also known as cohenite, particularly when found mixed with nickel and cobalt carbides in meteorites. This forms a hard, shiny, silver mineral which was first described by E. Weinschenk in 1889.

External links

* [http://www.msm.cam.ac.uk/phase-trans/2003/Lattices/cementite.html Crystal Structure of Cementite, Cambridge University]


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Look at other dictionaries:

  • Cementite — Cémentite Cet article est lié aux composés du fer et du carbone Fer Carbone …   Wikipédia en Français

  • cémentite — ● cémentite nom féminin (de cément) Carbure de fer (Fe3C). [Très dure et très fragile, la cémentite se trouve dans les aciers et les fontes blanches.] …   Encyclopédie Universelle

  • Cementite — Cementite. См. Цементит. (Источник: «Металлы и сплавы. Справочник.» Под редакцией Ю.П. Солнцева; НПО Профессионал , НПО Мир и семья ; Санкт Петербург, 2003 г.) …   Словарь металлургических терминов

  • cementite — s. f. 1.  [Mineralogia] Liga de ferro com o carbono (Fe3C). 2.  [Mineralogia] Lesão do cemento ocasionada por supurações alveolares.   ♦ Grafia no Brasil: cementita …   Dicionário da Língua Portuguesa

  • cementite — [sə men′tīt΄] n. [ CEMENT + ITE1] the hard, brittle carbide of iron, Fe3C, that occurs in and adds strength to steel, cast iron, and most other alloys of iron and carbon …   English World dictionary

  • Cémentite — Cet article est lié aux composés du fer et du carbone Fer Carbone Phases …   Wikipédia en Français

  • cementite — an iron carbide (Fe3C) constituent of steel. It is hard, brittle and crystalline. Steel which has cooled slowly from a high temperature contains ferrite and pearlite in relative proportions varying with the chemical composition of the steel.… …   Mechanics glossary

  • cementite — cementitas statusas T sritis chemija apibrėžtis Plieno struktūros elementas. formulė Fe₃C atitikmenys: angl. cementite rus. цементит …   Chemijos terminų aiškinamasis žodynas

  • cementite — noun Etymology: 1cement Date: 1888 a hard brittle iron carbide Fe3C that occurs in steel, cast iron, and iron carbon alloys …   New Collegiate Dictionary

  • cementite — /si men tuyt/, n. Metall. an iron carbide, Fe3C, a constituent of steel and cast iron, sometimes with part of its iron replaced by another metal, as manganese. [1885 90; CEMENT + ITE1] * * * …   Universalium

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