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wire drawing (logarithmic strain above 3) leads to pearlitic wires with yield strengths of several gigapascals. It makes pearlite one of the strongest structural bulk materials on earth. Some hypereutectoid pearlitic steel wires, when cold wire drawn to true (logarithmic) strains above 5, can even show a maximal tensile strength above 6 GPa (870 ksi). Although pearlite is used in many engineering applications, the origin of its extreme strength is not well understood. It has been recently shown that cold wire drawing not only strengthens pearlite by refining the lamellae structure, but also simultaneously causes partial chemical decomposition of cementite, associated with an increased carbon content of the ferrite phase, deformation induced lattice defects in ferrite lamellae, and even a structural transition from crystalline to amorphous cementite. The deformation-induced decomposition and microstructural change of cementite is closely related to several other phenomena such as a strong redistribution of carbon and other alloy elements like
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Steels with pearlitic (eutectoid composition) or near-pearlitic microstructure (near-eutectoid composition) can be drawn into thin wires. Such wires, often bundled into ropes, are commercially used as piano wires, ropes for suspension bridges, and as steel cord for tire reinforcement. High degrees of
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Eutectoid steel can in principle be transformed completely into pearlite; hypoeutectoid steels can also be completely pearlitic if transformed at a temperature below the normal eutectoid. Pearlite can be hard and strong but is not particularly
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in both the cementite and the ferrite phase; a variation of the deformation accommodation at the phase interfaces due to a change in the carbon concentration gradient at the interfaces; and mechanical alloying.
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and thus lacks this pearlescent appearance. It is prepared by more rapid cooling. Unlike pearlite, whose formation involves the diffusion of all atoms, bainite grows by a displacive transformation mechanism.
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Li, Y.; Raabe, D.; Herbig, M. J.; Choi, P.P.; Goto, S.; Kostka, A.; Yarita, H.; Bochers, C.; Kirchheim, R. (2014), "Segregation stabilizes nanocrystalline bulk steel with near theoretical strength",
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The transformation of pearlite to austenite takes place at lower critical temperature of 723 °C (1,333 °F). At this temperature pearlite changes to austenite because of nucleation process.
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Alvarenga HD, Van de Putte T, Van
Steenberge N, Sietsma J, Terryn H (Apr 2009). "Influence of Carbide Morphology and Microstructure on the Kinetics of Superficial Decarburization of C-Mn Steels".
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Chen, Y. Z.; Csiszár, G.; Cizek, J.; Westerkamp, S.; Borchers, C.; Ungár, T.; Goto, S.; Liu, F.; Kirchheim, R. (2013-04-10). "Defects in Carbon-Rich
Ferrite of Cold-Drawn Pearlitic Steel Wires".
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Li, Y.J.; Choi, P.P.; Borchers, C.; Westerkamp, S.; Goto, S.; Raabe, D.; Kirchheim, R. (2011), "Atomic-scale mechanisms of deformation-induced cementite decomposition in pearlite",
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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.
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cools below 723 °C (1,333 °F) (the eutectoid temperature). Pearlite is a microstructure occurring in many common grades of steels.
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Raabe, D.; Choi, P. P.; Li, Y. J.; Kostka, A.; Sauvage, X.; Lecouturier, F.; Hono, K.; Kirchheim, R.; Pippan, R.; Embury, D. (2010),
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and especially the optical effect caused by the scale of the structure made the alternative name more popular.
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Chapter 15 High-Carbon Steels: Fully
Pearlitic Microstructures and Applications
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and initially named sorbite, however the similarity of microstructure to
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by Sidney H. Avner, second edition, McGraw hill publications.
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The eutectoid composition of austenite is approximately 0.8%
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is a similar structure with lamellae much smaller than the
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of the iron-carbon phase diagram (near the lower left).
693:"Eutectoid Steel - Engineering Dictionary - EngNet"
60:. Unsourced material may be challenged and removed.
734:by George Krauss, 2005 Edition, ASM International.
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721:Steels: Processing, Structure, and Performance
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16:Lamellar structure of ferrite and cementite
573:Metallurgical and Materials Transactions A
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120:Learn how and when to remove this message
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710:Comprehensive information on pearlite
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337:micrograph of etched pearlite, 2000X.
58:adding citations to reliable sources
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715:Introduction to Physical metallurgy
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54:improve this article
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585:2013MMTA...44.3882C
542:2014PhRvL.113j6104L
438:Henry Clifton Sorby
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219:Tempered martensite
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321:Wrought iron
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52:Please help
47:verification
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665:: 123–133.
400:Composition
255:Alloy steel
199:Spheroidite
767:Metallurgy
761:Categories
499:References
452:wavelength
418:lever rule
386:cast irons
366:two-phased
306:White iron
280:Tool steel
214:Ledeburite
176:Martensite
80:newspapers
69:"Pearlite"
679:136871961
609:135839236
601:1073-5623
430:manganese
394:austenite
390:eutectoid
378:cementite
355:eutectoid
301:Gray iron
296:Cast iron
171:Cementite
166:Austenite
21:amorphous
751:Pearlite
728:Archived
558:25238372
370:lamellar
362:Pearlite
204:Pearlite
181:Graphite
19:For the
632:Bibcode
581:Bibcode
538:Bibcode
489:chisels
448:Bainite
426:silicon
374:ferrite
232:Classes
209:Bainite
161:Ferrite
94:scholar
25:perlite
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491:, and
485:knives
406:carbon
382:steels
152:Phases
136:Steels
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772:Steel
675:S2CID
605:S2CID
493:nails
481:wires
473:tough
442:nacre
364:is a
101:JSTOR
87:books
777:Iron
597:ISSN
554:PMID
428:and
384:and
73:news
667:doi
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335:SEM
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