Editing Pearlite (section)

{{Short description|Lamellar structure of ferrite and cementite}}
{{for|the [[amorphous]] volcanic glass|perlite}}
{{More citations needed|date=November 2010}}
{{Steels}}
[[Image:pearlite.jpg|thumb|[[Scanning electron microscope|SEM]] micrograph of etched pearlite, 2000X.]]

[[Image:Atom_probe_tomography_of_pearlite_after_wire_drawing.gif|thumb|Atom probe tomography of pearlite. The red dots indicate the positions of carbon atoms. Iron atoms are not shown. The nanotube is shown for size reference.]]

[[Image:Phase diag iron carbon.PNG|thumb|Pearlite occurs at the [[eutectoid]] of the iron-carbon phase diagram (near the lower left).]]

'''Pearlite''' is a [[Phase (matter)|two-phased]], [[Lamellar structure|lamellar]] (or layered) structure composed of alternating layers of [[Ferrite (iron)|ferrite]] (87.5 wt%) and [[cementite]] (12.5 wt%) that occurs in some [[steel]]s and [[cast iron]]s. During slow cooling of an iron-carbon alloy, pearlite forms by a [[eutectoid]] reaction as [[austenite]] cools below {{convert|723|C|abbr=on}} (the eutectoid temperature). Pearlite is a microstructure occurring in many common grades of steels.