Chromium carbide

Chromium carbide: Chromium carbide^[1]

IUPAC name

Chromium(II) carbide

Identifiers

CAS number 12012-35-0^Y

PubChem 3650773

ChemSpider 21171152^Y

Jmol-3D images Image 1

SMILES

[Cr]#C[Cr]C#[Cr]

InChI

InChI=1S/2C.3Cr^Y
Key: UFGZSIPAQKLCGR-UHFFFAOYSA-N^Y
InChI=1/2C.3Cr/rC2Cr3/c3-1-5-2-4
Key: UFGZSIPAQKLCGR-HMFAXLTNAU

Properties

Molecular formula Cr₃C₂

Molar mass 180.009 g/mol

Appearance gray orthorhombic crystals

Density 6.68 g/cm³

Melting point
1895°C

Structure

Crystal structure Orthorhombic, oP20

Space group Pnma, No. 62

Y carbide (verify) (what is: Y/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)

Infobox references

Chromium carbide (Cr₃C₂) is an extremely hard refractory ceramic material. It is usually processed by sintering. It has the appearance of a gray powder with orthorhombic crystal structure. The orthorhombic Cr₃C₂ occurs extremely rarely as mineral tongbaite.

Other compositions are available, e.g. Cr₂₃C₆ (occurring as extremely rare mineral isovite, cubic) and Cr₇C₃.

Contents

1 Properties

2 Uses

3 References

4 External links

Properties

It is highly corrosion-resistant, and does not oxidize at high temperatures (1000-1100 °C). The powder for coating costs $40–$65 per pound.

The thermal expansion coefficient of chromium carbide is almost equal to that of steel, reducing the mechanical stress buildup at the layer boundary.

Precipitation of chromium carbide at the grain boundaries, depleting the grain edges of chromium, is the cause of intergranular corrosion of stainless steel near the welds.

Uses

Chromium carbide is used as a thermal spray material for protecting the underlying metal surface, and as an additive to corrosion-resistant and wear-resistant materials. It is used in coatings of bearings, seals, orifices, and valve seals, and as a fine-crystal phase in other sintered carbides, where, like the vanadium carbide, it inhibits growth of submicrometre grains during pressing and sintering.

It is also used as a material for gage block standards, used in metrology. Chromium carbide is widely used by Starrett-Webber gage block tolerances, with a thermal expansion coefficient of 4.7 x 10^-6 inches/foot per inch.

References

^ Lide, David R. (1998), Handbook of Chemistry and Physics (87 ed.), Boca Raton, FL: CRC Press, pp. 4–52, ISBN 0-8493-0594-2

External links

National Pollutant Inventory - Chromium (III) compounds fact sheet

v · d · e Chromium compounds

Cr(CO)₆ · CrCl₂ · CrCl₃ · CrCl₄ · CrF₃ · CrN · Cr(NO₃)₃ · CrO · CrO₂ · CrO₃ · CrO₅ · Cr₂O₃ · Cr₂S₃ · Cr₂(SO₄)₃ · Cr₃C₂

Categories:
Carbides
Chromium compounds
Superhard materials
Refractory materials
Inorganic compound stubs

Chromium carbide^[1]

IUPAC name Chromium(II) carbide
Identifiers
CAS number	12012-35-0^Y
PubChem	3650773
ChemSpider	21171152^Y
Jmol-3D images	Image 1
SMILES [Cr]#C[Cr]C#[Cr]
InChI InChI=1S/2C.3Cr^Y Key: UFGZSIPAQKLCGR-UHFFFAOYSA-N^Y InChI=1/2C.3Cr/rC2Cr3/c3-1-5-2-4 Key: UFGZSIPAQKLCGR-HMFAXLTNAU
Properties
Molecular formula	Cr₃C₂
Molar mass	180.009 g/mol
Appearance	gray orthorhombic crystals
Density	6.68 g/cm³
Melting point	1895°C
Structure
Crystal structure	Orthorhombic, oP20
Space group	Pnma, No. 62
Y carbide (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

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Pyrolytic chromium carbide coating — (PCC) is a technology for protection and reworking of rapidly wearing parts of manufacturing equipment working in extreme environmental conditions, using vacuum deposition technology. Coating mechanical parts can help with problems of corrosion,… … Wikipedia
Carbide — For the software development tool targeting the Symbian OS, see Carbide.c++. Calcium carbide. In chemistry, a carbide is a compound composed of carbon and a less electronegative element. Carbides can be generally classified by chemical bonding… … Wikipedia
Chromium — This article is about the chemical element. For other uses, see Chromium (disambiguation). vanadium ← chromium → manganese ↑ Cr ↓ Mo … Wikipedia
chromium(III) carbide — chromo(III) karbidas statusas T sritis chemija formulė CrC₃ atitikmenys: angl. chromic carbide; chromium(III) carbide rus. хром углеродистый; хрома(III) карбид ryšiai: sinonimas – chromo trikarbidas … Chemijos terminų aiškinamasis žodynas
Chromium steel — Steel Steel (st[=e]l), n. [AS. st[=e]l, st[=y]l, st[=y]le; akin to D. staal, G. stahl, OHG. stahal, Icel. st[=a]l, Dan. staal, Sw. st[*a]l, Old Prussian stakla.] 1. (Metal) A variety of iron intermediate in composition and properties between… … The Collaborative International Dictionary of English
chromic carbide — chromo(III) karbidas statusas T sritis chemija formulė CrC₃ atitikmenys: angl. chromic carbide; chromium(III) carbide rus. хром углеродистый; хрома(III) карбид ryšiai: sinonimas – chromo trikarbidas … Chemijos terminų aiškinamasis žodynas
Intergranular corrosion — (IGC), also termed intergranular attack (IGA), is a form of corrosion where the boundaries of crystallites of the material are more susceptible to corrosion than their insides. ( Cf. transgranular corrosion.)This situation can happen in otherwise … Wikipedia
Arc welding — uses a welding power supply to create an electric arc between an electrode and the base material to melt the metals at the welding point. They can use either direct (DC) or alternating (AC) current, and consumable or non consumable electrodes.… … Wikipedia
Plating — describes surface covering where a metal is deposited on a conductive surface. Plating has been done for hundreds of years, but it is also critical for modern technology. Plating is used to decorate objects, for corrosion inhibition, to improve… … Wikipedia
niobium processing — Introduction preparation of the ore for use in various products. Niobium (Nb) has a body centred cubic (bcc) crystal structure and a melting point of 2,468° C (4,474° F). Of the refractory metals, it has the lowest density and best… … Universalium

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Chromium carbide

Contents

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Uses

References

External links

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Chromium carbide

Contents

Properties

Uses

References

External links

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