54:
457:(containing iron carbide, i.e. cementite, but no uncombined carbon) above 727 °C (1,341 °F) causes the formation of austenite in crystals of primary cementite. This austenisation of white iron occurs in primary cementite at the interphase boundary with ferrite. When the grains of austenite form in cementite, they occur as lamellar clusters oriented along the cementite crystal layer surface. Austenite is formed by diffusion of carbon atoms from cementite into ferrite.
241:
253:
393:
512:. The epitaxial growth of austenite on the diamond (100) face is feasible because of the close lattice match and the symmetry of the diamond (100) face is fcc. More than a monolayer of γ-iron can be grown because the critical thickness for the strained multilayer is greater than a monolayer. The determined critical thickness is in close agreement with theoretical prediction.
436:
which is much harder and will generate cracks at much lower strains. The volume change (martensite is less dense than austenite) can generate stresses as well. The difference in strain rates of the inner and outer portion of the part may cause cracks to develop in the outer portion, compelling the use of slower quenching rates to avoid this. By alloying the steel with
435:
A high cooling rate of thick sections will cause a steep thermal gradient in the material. The outer layers of the heat treated part will cool faster and shrink more, causing it to be under tension and thermal straining. At high cooling rates, the material will transform from austenite to martensite
383:
By changing the temperature for austenitization, the austempering process can yield different and desired microstructures. A higher austenitization temperature can produce a higher carbon content in austenite, whereas a lower temperature produces a more uniform distribution of austempered structure.
560:
of the work, with the transition from a deep cherry-red to orange-red (815 °C (1,499 °F) to 871 °C (1,600 °F)) corresponding to the formation of austenite in medium and high-carbon steel. In the visible spectrum, this glow increases in brightness as temperature increases. When
444:
following quenching will transform some of the brittle martensite into tempered martensite. If a low-hardenability steel is quenched, a significant amount of austenite will be retained in the microstructure, leaving the steel with internal stresses that leave the product prone to sudden fracture.
338:
means to heat the iron, iron-based metal, or steel to a temperature at which it changes crystal structure from ferrite to austenite. The more-open structure of the austenite is then able to absorb carbon from the iron-carbides in carbon steel. An incomplete initial austenitization can leave
323:(FCC) configuration of gamma iron, also called austenite. This is similarly soft and ductile but can dissolve considerably more carbon (as much as 2.03% by mass at 1,146 °C (2,095 °F)). This gamma form of iron is present in the most commonly used type of
53:
375:
and then quenched in a salt bath or other heat extraction medium that is between temperatures of 300–375 °C (572–707 °F). The metal is annealed in this temperature range until the austenite turns to
561:
cherry-red, the glow is near its lowest intensity and may not be visible in ambient light. Hence blacksmiths usually austenitize steel in low-light conditions to accurately judge the color of the glow.
548:
causes phase changes in the iron-carbon system to control the material's mechanical properties, often using the annealing, quenching, and tempering processes. In this context, the color of light, or "
917:
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".
440:, the carbon diffusion is slowed and the transformation to BCT allotrope occurs at lower temperatures, thereby avoiding the cracking. Such a material is said to have its hardenability increased.
424:(BCT). The rate of cooling determines the relative proportions of martensite, ferrite, and cementite, and therefore determines the mechanical properties of the resulting steel, such as
524:, the temperature at which magnetic materials cease to behave magnetically, occurs at nearly the same temperature as the austenite transformation. This behavior is attributed to the
1049:
696:
653:
Lambers HG, Tschumak S, Maier HJ, Canadinc D (Apr 2009). "Role of
Austenitization and Pre-Deformation on the Kinetics of the Isothermal Bainitic Transformation".
635:
346:
For some iron metals, iron-based metals, and steels, the presence of carbides may occur during the austenitization step. The term commonly used for this is
303:(1843–1902). It exists at room temperature in some stainless steels due to the presence of nickel stabilizing the austenite at lower temperatures.
1106:
1074:
851:
603:
408:, may form. If the rate of cooling is very swift, the carbon does not have sufficient time to diffuse, and the alloy may experience a large
400:
As austenite cools, the carbon diffuses out of the austenite and forms carbon-rich iron-carbide (cementite) and leaves behind carbon-poor
1009:
504:
Austenite is only stable above 910 °C (1,670 °F) in bulk metal form. However, fcc transition metals can be grown on a
965:
Hoff HA, Waytena GL, Glesener JW, Harris VG, Pappas DP (Mar 1995). "Critical thickness of single crystal fcc iron on diamond".
799:
Chupatanakul S, Nash P (Aug 2006). "Dilatometric measurement of carbon enrichment in austenite during bainite transformation".
300:
1010:"Effect of rolling strain on transformation induced plasticity of austenite to martensite in a high-alloy austenitic steel"
712:"The Strain-Hardening Behavior of Partially Austenitized and the Austempered Ductile Irons with Dual Matrix Structures"
478:
413:
421:
133:
441:
128:
1098:
1043:
974:
926:
883:
808:
723:
662:
505:
549:
368:
to promote better mechanical properties. The metal is heated into the austenite region of the iron-
320:
316:
990:
942:
899:
824:
781:
739:
678:
575:
401:
288:
272:
70:
1102:
1070:
847:
599:
557:
409:
27:
Metallic, non-magnetic allotrope of iron or a solid solution of iron, with an alloying element
1064:
1090:
1024:
982:
934:
891:
816:
773:
761:
731:
711:
670:
429:
312:
184:
179:
240:
1127:
474:
324:
174:
384:
The carbon content in austenite as a function of austempering time has been established.
978:
930:
887:
812:
727:
666:
276:
225:
169:
149:
99:
61:
1121:
1028:
986:
946:
903:
828:
785:
743:
682:
541:
529:
509:
372:
994:
252:
844:
Engineering
Materials 2: An Introduction to Microstructures, Processing, and Design
525:
481:, much higher alloy content makes this structure stable even at room temperature.
359:
230:
220:
159:
154:
874:
Ershov VM, Nekrasova LS (Jan 1982). "Transformation of cementite into austenite".
299:
have different eutectoid temperatures. The austenite allotrope is named after Sir
521:
164:
108:
777:
938:
820:
735:
674:
570:
553:
545:
489:
417:
404:. Depending on alloy composition, a layering of ferrite and cementite, called
392:
215:
189:
123:
85:
37:
This article is about the alloy and iron allotrope. For Jane Austen fans, see
466:
454:
369:
292:
210:
205:
80:
31:
762:"Effect of austenitization on austempering of copper alloyed ductile iron"
311:
From 912 to 1,394 °C (1,674 to 2,541 °F) alpha iron undergoes a
17:
623:. Springfield, Massachusetts, USA: G & C Merriam Company. p. 58.
493:
473:, can stabilize the austenitic structure, facilitating heat-treatment of
437:
425:
405:
113:
90:
895:
485:
377:
340:
118:
38:
470:
1008:
M. Bigdeli
Karimia, H. Arabib, A. Khosravania, and J. Samei (2008).
528:
nature of austenite, while both martensite and ferrite are strongly
496:
tend to de-stabilize austenite, raising the eutectoid temperature.
365:
296:
284:
251:
239:
280:
364:
Austempering is a hardening process that is used on iron-based
244:
Iron-carbon phase diagram, showing the conditions under which
380:
or ausferrite (bainitic ferrite + high-carbon austenite).
1066:
Reducing
Brittle and Fatigue Failures in Steel Structures
636:"Quenching and tempering of welded carbon steel tubulars"
396:
Austenite microstructure at two different temperatures
536:
Thermo-optical emission, colour indicates temperature
295:
temperature of 1000 K (727 °C); other alloys of
465:The addition of certain alloying elements, such as
1069:, New York: American Society of Civil Engineers,
766:Journal of Materials Engineering and Performance
327:for making hospital and food-service equipment.
556:. Temperature is often gauged by watching the
552:", emitted by the workpiece is an approximate
598:(3rd ed.). Boston: PWS-Kent Publishing.
256:Allotropes of iron; alpha iron and gamma iron
8:
1048:: CS1 maint: multiple names: authors list (
621:Webster's Seventh New Collegiate Dictionary
1017:Journal of Materials Processing Technology
43:
869:
867:
865:
863:
842:Ashby MF, Hunkin-Jones DR (1986-01-01).
391:
960:
958:
956:
755:
753:
586:
197:
141:
98:
60:
46:
1041:
291:, austenite exists above the critical
760:Batra U, Ray S, Prabhakar SR (2003).
520:In many magnetic ferrous alloys, the
7:
484:On the other hand, such elements as
461:Stabilization at lower temperatures
594:Reed-Hill R, Abbaschian R (1991).
422:body centered tetragonal structure
25:
1029:10.1016/j.jmatprotec.2007.10.029
52:
301:William Chandler Roberts-Austen
271:), is a metallic, non-magnetic
596:Physical Metallurgy Principles
516:Transformation and Curie point
388:Behavior in plain carbon-steel
248:(γ) is stable in carbon steel.
1:
710:Kilicli V, Erdogan M (2008).
987:10.1016/0039-6028(94)00787-X
416:in which it transforms into
634:Nichols R (July 29, 2001).
1144:
778:10.1361/105994903100277120
479:austenitic stainless steel
414:martensitic transformation
357:
198:Other iron-based materials
36:
29:
1095:Chemistry of the Elements
1093:; Earnshaw, Alan (1997).
939:10.1007/s11661-014-2600-y
821:10.1007/s10853-006-0127-3
736:10.1007/s11665-007-9143-y
675:10.1007/s11661-009-9827-z
477:. In the extreme case of
348:two-phase austenitization
1063:Maranian, Peter (2009),
134:Widmanstätten structures
30:Not to be confused with
397:
257:
249:
1099:Butterworth-Heinemann
1091:Greenwood, Norman N.
619:Gove PB, ed. (1963).
449:Behavior in cast iron
395:
255:
243:
919:Metall Mater Trans A
876:Metal Sci Heat Treat
655:Metall Mater Trans A
554:gauge of temperature
412:distortion known as
979:1995SurSc.326..252H
931:2015MMTA...46..123A
888:1982MSHT...24....9E
813:2006JMatS..41.4965C
728:2008JMEP...17..240K
667:2009MMTA...40.1355L
550:blackbody radiation
506:face-centered cubic
321:face-centered cubic
317:body-centered cubic
129:Tempered martensite
896:10.1007/BF00699307
576:Allotropes of iron
398:
289:plain-carbon steel
258:
250:
1108:978-0-08-037941-8
1076:978-0-7844-1067-7
853:978-0-080-32532-3
697:"Austenitization"
605:978-0-534-92173-6
558:color temperature
307:Allotrope of iron
273:allotrope of iron
238:
237:
16:(Redirected from
1135:
1113:
1112:
1097:(2nd ed.).
1087:
1081:
1080:
1060:
1054:
1053:
1047:
1039:
1037:
1035:
1023:(1–3): 349–354.
1014:
1005:
999:
998:
962:
951:
950:
914:
908:
907:
871:
858:
857:
839:
833:
832:
796:
790:
789:
757:
748:
747:
716:J Mater Eng Perf
707:
701:
700:
693:
687:
686:
661:(6): 1355–1366.
650:
644:
643:
631:
625:
624:
616:
610:
609:
591:
475:low-alloy steels
430:tensile strength
313:phase transition
265:gamma-phase iron
263:, also known as
185:Weathering steel
180:High-speed steel
56:
44:
21:
1143:
1142:
1138:
1137:
1136:
1134:
1133:
1132:
1118:
1117:
1116:
1109:
1089:
1088:
1084:
1077:
1062:
1061:
1057:
1040:
1033:
1031:
1012:
1007:
1006:
1002:
964:
963:
954:
916:
915:
911:
873:
872:
861:
854:
841:
840:
836:
798:
797:
793:
759:
758:
751:
709:
708:
704:
695:
694:
690:
652:
651:
647:
633:
632:
628:
618:
617:
613:
606:
593:
592:
588:
584:
567:
538:
518:
502:
463:
451:
390:
362:
356:
343:in the matrix.
336:Austenitization
333:
325:stainless steel
309:
175:Stainless steel
100:Microstructures
42:
35:
28:
23:
22:
15:
12:
11:
5:
1141:
1139:
1131:
1130:
1120:
1119:
1115:
1114:
1107:
1082:
1075:
1055:
1000:
952:
925:(1): 123–133.
909:
859:
852:
834:
807:(15): 4965–9.
791:
772:(5): 597–601.
749:
702:
688:
645:
640:The Fabricator
626:
611:
604:
585:
583:
580:
579:
578:
573:
566:
563:
537:
534:
517:
514:
501:
498:
462:
459:
453:Heating white
450:
447:
389:
386:
358:Main article:
355:
352:
332:
329:
308:
305:
277:solid solution
236:
235:
234:
233:
228:
226:Malleable iron
223:
218:
213:
208:
200:
199:
195:
194:
193:
192:
187:
182:
177:
172:
170:Maraging steel
167:
162:
157:
152:
150:Crucible steel
144:
143:
139:
138:
137:
136:
131:
126:
121:
116:
111:
103:
102:
96:
95:
94:
93:
88:
83:
78:
73:
65:
64:
58:
57:
49:
48:
26:
24:
14:
13:
10:
9:
6:
4:
3:
2:
1140:
1129:
1126:
1125:
1123:
1110:
1104:
1100:
1096:
1092:
1086:
1083:
1078:
1072:
1068:
1067:
1059:
1056:
1051:
1045:
1030:
1026:
1022:
1018:
1011:
1004:
1001:
996:
992:
988:
984:
980:
976:
973:(3): 252–66.
972:
968:
961:
959:
957:
953:
948:
944:
940:
936:
932:
928:
924:
920:
913:
910:
905:
901:
897:
893:
889:
885:
881:
877:
870:
868:
866:
864:
860:
855:
849:
845:
838:
835:
830:
826:
822:
818:
814:
810:
806:
802:
795:
792:
787:
783:
779:
775:
771:
767:
763:
756:
754:
750:
745:
741:
737:
733:
729:
725:
721:
717:
713:
706:
703:
698:
692:
689:
684:
680:
676:
672:
668:
664:
660:
656:
649:
646:
641:
637:
630:
627:
622:
615:
612:
607:
601:
597:
590:
587:
581:
577:
574:
572:
569:
568:
564:
562:
559:
555:
551:
547:
543:
542:heat treating
535:
533:
531:
530:ferromagnetic
527:
523:
515:
513:
511:
510:diamond cubic
507:
499:
497:
495:
491:
487:
482:
480:
476:
472:
468:
460:
458:
456:
448:
446:
443:
439:
433:
431:
427:
423:
419:
415:
411:
407:
403:
394:
387:
385:
381:
379:
374:
373:phase diagram
371:
367:
361:
353:
351:
349:
344:
342:
337:
330:
328:
326:
322:
319:(BCC) to the
318:
314:
306:
304:
302:
298:
294:
290:
286:
282:
278:
274:
270:
266:
262:
254:
247:
242:
232:
229:
227:
224:
222:
219:
217:
214:
212:
209:
207:
204:
203:
202:
201:
196:
191:
188:
186:
183:
181:
178:
176:
173:
171:
168:
166:
163:
161:
158:
156:
153:
151:
148:
147:
146:
145:
140:
135:
132:
130:
127:
125:
122:
120:
117:
115:
112:
110:
107:
106:
105:
104:
101:
97:
92:
89:
87:
84:
82:
79:
77:
74:
72:
69:
68:
67:
66:
63:
59:
55:
51:
50:
45:
40:
33:
19:
1094:
1085:
1065:
1058:
1044:cite journal
1032:. Retrieved
1020:
1016:
1003:
970:
966:
922:
918:
912:
879:
875:
843:
837:
804:
800:
794:
769:
765:
722:(2): 240–9.
719:
715:
705:
691:
658:
654:
648:
639:
629:
620:
614:
595:
589:
539:
526:paramagnetic
519:
503:
483:
464:
452:
434:
399:
382:
363:
360:Austempering
354:Austempering
347:
345:
339:undissolved
335:
334:
310:
287:element. In
268:
264:
260:
259:
245:
231:Wrought iron
221:Ductile iron
160:Spring steel
155:Carbon steel
75:
1034:4 September
882:(1): 9–11.
801:J Mater Sci
522:Curie point
165:Alloy steel
109:Spheroidite
582:References
571:Gamma loop
546:blacksmith
500:Thin films
490:molybdenum
418:martensite
216:White iron
190:Tool steel
124:Ledeburite
86:Martensite
18:Austenitic
947:136871961
904:136543311
829:137527848
786:135865284
744:135484622
683:136882327
508:(fcc) or
467:manganese
455:cast iron
442:Tempering
370:cementite
293:eutectoid
261:Austenite
246:austenite
211:Gray iron
206:Cast iron
81:Cementite
76:Austenite
32:Austinite
1122:Category
995:93826286
967:Surf Sci
565:See also
494:chromium
438:tungsten
426:hardness
406:pearlite
341:carbides
331:Material
285:alloying
283:with an
114:Pearlite
91:Graphite
975:Bibcode
927:Bibcode
884:Bibcode
809:Bibcode
724:Bibcode
663:Bibcode
540:During
486:silicon
410:lattice
402:ferrite
378:bainite
142:Classes
119:Bainite
71:Ferrite
39:Janeite
1128:Steels
1105:
1073:
993:
945:
902:
850:
827:
784:
742:
681:
602:
492:, and
471:nickel
366:metals
62:Phases
47:Steels
1013:(PDF)
991:S2CID
943:S2CID
900:S2CID
825:S2CID
782:S2CID
740:S2CID
679:S2CID
315:from
297:steel
275:or a
1103:ISBN
1071:ISBN
1050:link
1036:2019
848:ISBN
600:ISBN
544:, a
469:and
428:and
420:, a
281:iron
269:γ-Fe
1025:doi
1021:203
983:doi
971:326
935:doi
892:doi
817:doi
774:doi
732:doi
671:doi
432:.
279:of
1124::
1101:.
1046:}}
1042:{{
1019:.
1015:.
989:.
981:.
969:.
955:^
941:.
933:.
923:46
921:.
898:.
890:.
880:24
878:.
862:^
846:.
823:.
815:.
805:41
803:.
780:.
770:12
768:.
764:.
752:^
738:.
730:.
720:17
718:.
714:.
677:.
669:.
659:40
657:.
638:.
532:.
488:,
350:.
1111:.
1079:.
1052:)
1038:.
1027::
997:.
985::
977::
949:.
937::
929::
906:.
894::
886::
856:.
831:.
819::
811::
788:.
776::
746:.
734::
726::
699:.
685:.
673::
665::
642:.
608:.
267:(
41:.
34:.
20:)
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
