{"id":3823,"date":"2019-06-04T05:42:01","date_gmt":"2019-06-04T05:42:01","guid":{"rendered":"https:\/\/www.meetyoucarbide.com\/?p=3823"},"modified":"2020-05-07T02:09:59","modified_gmt":"2020-05-07T02:09:59","slug":"common-microstructures-of-metal-and-alloy","status":"publish","type":"post","link":"https:\/\/www.meetyoucarbide.com\/tr\/common-microstructures-of-metal-and-alloy\/","title":{"rendered":"8 Metal ve Ala\u015f\u0131m\u0131n Ortak Mikro Yap\u0131lar\u0131"},"content":{"rendered":"
\n

Modern malzemeler d\u00f6rt kategoriye ayr\u0131labilir: metaller, polimerler, seramikler ve kompozit malzemeler. Makromolek\u00fcl malzemelerin h\u0131zl\u0131 geli\u015fimine ra\u011fmen \u00e7elik, mevcut m\u00fchendislik teknolojisinde hala en yayg\u0131n kullan\u0131lan ve en \u00f6nemli malzemedir. \u00c7elik malzemelerin bask\u0131n konumunu hangi fakt\u00f6rler belirler? \u015eimdi detayl\u0131 olarak tan\u0131tal\u0131m.<\/p>\n\n\n\n

Demir ve \u00e7elik, kaynaklar\u0131 zengin ve fiyat\u0131 d\u00fc\u015f\u00fck olan demir cevherinden \u00e7\u0131kar\u0131l\u0131r. Demir-karbon ala\u015f\u0131m\u0131 olarak da bilinen demir ve \u00e7elik, demir (Fe) ve karbon (C), silikon (Si), manganez (Mn), fosfor (P), k\u00fck\u00fcrt (S) ve di\u011fer k\u00fc\u00e7\u00fck elementlerden olu\u015fan bir ala\u015f\u0131md\u0131r. (Kr, V, vb.). \u00c7elikte \u00e7e\u015fitli elementlerin i\u00e7eri\u011fi ve \u0131s\u0131l i\u015flem (d\u00f6rt pi\u015firim: su verme, tavlama, tavlama, normalle\u015ftirme) ayarlanarak \u00e7e\u015fitli metalografik yap\u0131lar elde edilebilir, b\u00f6ylece \u00e7eli\u011fin farkl\u0131 fiziksel \u00f6zelliklere sahip olmas\u0131 sa\u011flan\u0131r. Metalografik mikroskop alt\u0131nda g\u00f6zlemlenen yap\u0131ya, \u00e7eli\u011fin belirli bir a\u015f\u0131nd\u0131r\u0131c\u0131 madde ile numune al\u0131nmas\u0131, \u00f6\u011f\u00fct\u00fclmesi, parlat\u0131lmas\u0131 ve da\u011flanmas\u0131ndan sonra metalografik yap\u0131 denir. \u00c7elik malzemelerin s\u0131rlar\u0131 bu yap\u0131larda gizlidir.<\/p>\n\n\n\n

        Fe-Fe3C sisteminde farkl\u0131 bile\u015fimlerde demir-karbon ala\u015f\u0131mlar\u0131 haz\u0131rlanabilmektedir. Denge yap\u0131lar\u0131 farkl\u0131 s\u0131cakl\u0131klarda farkl\u0131d\u0131r, ancak birka\u00e7 temel fazdan olu\u015furlar (ferrit F, \u00f6stenit A ve sementit Fe3C). Bu temel fazlar, \u00e7elikte zengin ve renkli bir metalografik yap\u0131 olu\u015fturan mekanik kar\u0131\u015f\u0131mlar \u015feklinde birle\u015ftirilir. Sekiz ortak metalografik yap\u0131 vard\u0131r:<\/p>\n\n\n\n

I. Ferrit<\/h2>\n\n\n\n

 A-Fe kafesinin arayerinde karbonun \u00e7\u00f6z\u00fclmesiyle olu\u015fan arayer kat\u0131 \u00e7\u00f6zeltisine ferrit denir ve BCC Yap\u0131s\u0131na ait olan ve F sembol\u00fc ile ifade edilen e\u015f eksenli \u00e7okgen tane da\u011f\u0131l\u0131m\u0131d\u0131r. Yap\u0131s\u0131 ve \u00f6zellikleri saf demire benzer. \u0130yi bir plastisite ve toklu\u011fa sahiptir, ancak mukavemeti ve sertli\u011fi daha d\u00fc\u015f\u00fckt\u00fcr (30-100 HB). Ala\u015f\u0131ml\u0131 \u00e7elikte, alfa-Fe'de karbon ve ala\u015f\u0131m elementlerinin kat\u0131 bir \u00e7\u00f6zeltisidir. Karbonun alfa-Fe i\u00e7indeki \u00e7\u00f6z\u00fcn\u00fcrl\u00fc\u011f\u00fc \u00e7ok d\u00fc\u015f\u00fckt\u00fcr. AC1 s\u0131cakl\u0131\u011f\u0131nda, karbonun maksimum \u00e7\u00f6z\u00fcn\u00fcrl\u00fc\u011f\u00fc 0,0218%'dir, ancak s\u0131cakl\u0131\u011f\u0131n d\u00fc\u015fmesiyle \u00e7\u00f6z\u00fcn\u00fcrl\u00fck 0,0084%'ye d\u00fc\u015fer. Bu nedenle, \u00fc\u00e7\u00fcnc\u00fc sementit, yava\u015f so\u011fuma ko\u015fullar\u0131nda ferrit tane s\u0131n\u0131r\u0131nda belirir. \u00c7elikteki karbon i\u00e7eri\u011finin artmas\u0131yla ferrit say\u0131s\u0131 azal\u0131r ve perlit say\u0131s\u0131 artar. \u015eu anda, ferrit a\u011f ve hilaldir.<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

\u2161.\u00d6stenit<\/h2>\n\n\n\n

 Gama-Fe kafesinin arayer bo\u015flu\u011funda karbonun \u00e7\u00f6z\u00fcnmesiyle olu\u015fan arayer kat\u0131 \u00e7\u00f6zeltisine \u00f6stenit denir. Y\u00fczey merkezli k\u00fcbik bir yap\u0131ya sahiptir ve A sembol\u00fc ile temsil edilen y\u00fcksek s\u0131cakl\u0131k faz\u0131d\u0131r. Ostenitin maksimum \u00e7\u00f6z\u00fcn\u00fcrl\u00fc\u011f\u00fc 1148 C'de 2.11% C ve kat\u0131 \u00e7\u00f6zeltisi 727 C'de 0.77% C'dir. Mukavemeti ve sertli\u011fi ferritten daha y\u00fcksek, plastisitesi ve toklu\u011fu iyidir ve manyetik de\u011fildir. Spesifik mekanik \u00f6zellikleri, genellikle 170-220 HBS, = 40-50% olmak \u00fczere karbon i\u00e7eri\u011fi ve tane boyutu ile ilgilidir. TRIP \u00e7eli\u011fi, ostenitin iyi plastisitesi ve esnekli\u011fi temelinde geli\u015ftirilmi\u015f bir \u00e7eliktir. Gerinim kaynakl\u0131 transformasyon ve tutulan ostenitin transformasyon kaynakl\u0131 plastisitesi, \u00e7elik levhan\u0131n plastisitesini ve \u00e7elik levhan\u0131n \u015fekillendirilebilirli\u011fini geli\u015ftirmek i\u00e7in kullan\u0131l\u0131r. Karbon veya ala\u015f\u0131ml\u0131 yap\u0131 \u00e7eliklerindeki \u00f6stenit, so\u011fuma s\u0131ras\u0131nda ba\u015fka fazlara d\u00f6n\u00fc\u015f\u00fcr. Sadece y\u00fcksek karbonlu \u00e7eliklerin ve karbonlanm\u0131\u015f \u00e7eliklerin karbonlama ve y\u00fcksek s\u0131cakl\u0131kta su vermesinden sonra, \u00f6stenit martensit bo\u015flu\u011funda kalabilir ve metalografik yap\u0131s\u0131, a\u015f\u0131nmas\u0131 kolay olmad\u0131\u011f\u0131 i\u00e7in beyazd\u0131r.<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

\u2162. sementit<\/h2>\n\n\n\n

 Sementit, belirli bir oranda karbon ve demir taraf\u0131ndan sentezlenen metal bir bile\u015fiktir. Fe3C molek\u00fcl form\u00fcl\u00fc, karbon i\u00e7eri\u011finin 6.69% oldu\u011funu ve ala\u015f\u0131mda (Fe, M) 3C olu\u015ftu\u011funu g\u00f6sterir. Sementit sert ve k\u0131r\u0131lgand\u0131r, plastisitesi ve darbe toklu\u011fu s\u0131f\u0131ra yak\u0131nd\u0131r, k\u0131r\u0131lganl\u0131\u011f\u0131 \u00e7ok y\u00fcksektir ve sertli\u011fi 800HB'dir. Demir ve \u00e7elikte da\u011f\u0131t\u0131m genellikle a\u011f, yar\u0131 a\u011f, pul, i\u011fne pul ve gran\u00fcld\u00fcr.<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

 IV. perlit<\/h2>\n\n\n\n

 Perlit, P sembol\u00fc ile ifade edilen, ferrit ve sementitin mekanik bir kar\u0131\u015f\u0131m\u0131d\u0131r. Mekanik \u00f6zellikleri, y\u00fcksek mukavemet, orta sertlik ve belirli bir plastisite ile ferrit ve sementit aras\u0131ndad\u0131r. Perlit, \u00e7elikte \u00f6tektoid d\u00f6n\u00fc\u015f\u00fcm\u00fcn bir \u00fcr\u00fcn\u00fcd\u00fcr. Morfolojisi, ferrit ve sementitin parmak izleri gibi katmanlar halinde d\u00fczenlenmesidir. Karb\u00fcrlerin da\u011f\u0131l\u0131m modeline g\u00f6re iki tipe ayr\u0131labilir: pul perlit ve k\u00fcresel perlit.<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

 a. Pul perlit: \u00dc\u00e7 tipe ayr\u0131labilir: kal\u0131n pul, orta pul ve ince pul.<\/p>\n\n\n\n

b. K\u00fcresel perlit: tavlaman\u0131n k\u00fcreselle\u015ftirilmesiyle elde edilen sementit k\u00fcreselle\u015ftirilir ve ferrit matrisi \u00fczerine da\u011f\u0131t\u0131l\u0131r. sementit sferoidlerin boyutu sferoidle\u015ftirme tavlama i\u015flemine, \u00f6zellikle so\u011futma h\u0131z\u0131na ba\u011fl\u0131d\u0131r. K\u00fcresel perlit d\u00f6rt tipe ayr\u0131labilir: kaba k\u00fcresel, k\u00fcresel, ince k\u00fcresel ve noktal\u0131.<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

V. Beynit<\/h2>\n\n\n\n

Beynit, \u00f6stenitin perlit d\u00f6n\u00fc\u015f\u00fcm b\u00f6lgesinin alt\u0131nda ve orta s\u0131cakl\u0131k b\u00f6lgesinde MS noktas\u0131n\u0131n \u00fcst\u00fcnde d\u00f6n\u00fc\u015f\u00fcm\u00fcn\u00fcn \u00fcr\u00fcn\u00fcd\u00fcr. Beynit, B sembol\u00fc ile ifade edilen, perlit ve martensit aras\u0131ndaki bir yap\u0131 olan ferrit ve sementitin mekanik bir kar\u0131\u015f\u0131m\u0131d\u0131r. Olu\u015fum s\u0131cakl\u0131\u011f\u0131na g\u00f6re gran\u00fcler beynit, \u00fcst beynit (\u00fcst B) ve alt beynit (alt B) olarak ayr\u0131labilir. Gran\u00fcl beynit d\u00fc\u015f\u00fck mukavemete sahiptir ancak iyi toklu\u011fa sahiptir. alt beynit hem y\u00fcksek mukavemete hem de iyi toklu\u011fa sahiptir. taneli beynit en k\u00f6t\u00fc toklu\u011fa sahiptir. Beynit morfolojisi de\u011fi\u015fkendir. Beyit, \u015fekil \u00f6zelliklerine g\u00f6re \u00fc\u00e7 t\u00fcre ayr\u0131labilir: t\u00fcy, i\u011fne ve gran\u00fcl.<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

a. \u00dcst beynit: <\/h3>\n\n\n\n

\u00dcst beynit, ince \u015ferit (veya k\u0131sa \u00e7ubuk) sementit ile ferrit i\u011fne eksenine paralel, t\u00fcyl\u00fc \u015ferit ferritin paralel d\u00fczenlenmesi ile karakterize edilir.<\/p>\n\n\n\n

b. Alt beynit: <\/h3>\n\n\n\n

ince i\u011fne pulu, belirli bir y\u00f6nelime sahip, erozyona kar\u015f\u0131 s\u00f6nd\u00fcr\u00fclm\u00fc\u015f martensite g\u00f6re daha hassas, temperlenmi\u015f martensite \u00e7ok benzer, \u0131\u015f\u0131k mikroskobu alt\u0131nda ay\u0131rt edilmesi \u00e7ok zor, elektron mikroskobu alt\u0131nda ay\u0131rt edilmesi kolay. karb\u00fcr i\u011fneli ferrit i\u00e7inde \u00e7\u00f6kelir ve hizalama oryantasyonu, ferrit levhan\u0131n uzun ekseni ile 55-60 derecedir, alt beynit ikiz i\u00e7ermez, daha fazla \u00e7\u0131k\u0131k vard\u0131r.<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

c. Gran\u00fcl beynit: <\/h3>\n\n\n\n

\u00c7okgen \u015fekilli ve bir\u00e7ok d\u00fczensiz ada benzeri yap\u0131ya sahip ferrit. \u00c7eli\u011fin osteniti, \u00fcst beynitin olu\u015fum s\u0131cakl\u0131\u011f\u0131ndan biraz daha y\u00fcksek bir s\u0131cakl\u0131\u011fa so\u011futuldu\u011funda, \u00e7\u00f6kelmi\u015f ferritin baz\u0131 karbon atomlar\u0131, ferrit\/ostenit faz s\u0131n\u0131r\u0131 boyunca ferritten ostenite g\u00f6\u00e7 eder, bu da osteniti e\u015fit olmayan bir \u015fekilde karbon a\u00e7\u0131s\u0131ndan zengin yapar, b\u00f6ylece \u00f6stenit i\u00e7in ferrit. Bu ostenit b\u00f6lgeleri genellikle ada benzeri, tanecikli veya \u015ferit benzeri olup, ferrit matris \u00fczerinde da\u011f\u0131lm\u0131\u015ft\u0131r. S\u00fcrekli so\u011futma s\u0131ras\u0131nda, \u00f6stenitin bile\u015fimine ve so\u011futma ko\u015fullar\u0131na g\u00f6re, tah\u0131l kefaletlerindeki \u00f6stenit a\u015fa\u011f\u0131daki de\u011fi\u015fikliklere u\u011frayabilir.<\/p>\n\n\n\n

(i) Tamamen veya k\u0131smen ferrit ve karbide ayr\u0131\u015fma. Elektron mikroskobu alt\u0131nda, \u00e7ok y\u00f6nl\u00fc da\u011f\u0131l\u0131ma sahip gran\u00fcler, \u00e7ubuk veya k\u00fc\u00e7\u00fck blok karb\u00fcrler g\u00f6r\u00fclebilir.<\/p>\n\n\n\n

(ii) \u0131\u015f\u0131k mikroskobu alt\u0131nda tamamen sar\u0131 olan martensite k\u0131smi d\u00f6n\u00fc\u015f\u00fcm.<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

(iii) hala karbonca zengin ostenit i\u00e7erir.<\/p>\n\n\n\n

Gran\u00fcler karb\u00fcrler, gran\u00fcler beynitin ferrit matrisi \u00fczerinde da\u011f\u0131t\u0131l\u0131r (ada yap\u0131s\u0131 orijinal olarak, so\u011futuldu\u011funda ferrit ve karbide ayr\u0131\u015fan veya martensite d\u00f6n\u00fc\u015fen veya karbonca zengin \u00f6stenit par\u00e7ac\u0131klar\u0131 olarak kalan karbonca zengin \u00f6stenittir). T\u00fcy beynit, ferrit matris, ferrit levhan\u0131n kenar\u0131nda \u00e7\u00f6keltilmi\u015f \u015ferit karb\u00fcr. Alt beynit, k\u00fc\u00e7\u00fck pul karb\u00fcr ile asik\u00fcler ferrit, uzun eksenin ferritindeki pul karb\u00fcr kabaca 55 ~ 60 derece a\u00e7\u0131d\u0131r. <\/p>\n\n\n\n

VI. WEISHER DOKUSU<\/h2>\n\n\n\n

Widmanstatten yap\u0131s\u0131, birbirini yakla\u015f\u0131k 60 derece kesen ve \u00e7elik matrise g\u00f6m\u00fcl\u00fc ferrit i\u011fnelerden olu\u015fan bir t\u00fcr a\u015f\u0131r\u0131 \u0131s\u0131t\u0131lm\u0131\u015f yap\u0131d\u0131r. Kaba Widmanstatten yap\u0131s\u0131 \u00e7eli\u011fin plastisitesini ve toklu\u011funu azalt\u0131r ve k\u0131r\u0131lganl\u0131\u011f\u0131n\u0131 artt\u0131r\u0131r. \u00d6tektoid alt\u0131 \u00e7elikte, a\u015f\u0131r\u0131 \u0131s\u0131nma ile kaba taneler olu\u015fur ve so\u011furken h\u0131zla \u00e7\u00f6ker. Bu nedenle, \u00f6stenit tane s\u0131n\u0131r\u0131 boyunca a\u011f \u00e7\u00f6kelmesine ek olarak, tane s\u0131n\u0131r\u0131ndan taneye kesme mekanizmas\u0131na uygun olarak baz\u0131 ferritler olu\u015fur ve ayr\u0131 ayr\u0131 i\u011fneler halinde \u00e7\u00f6keltilir. Bu da\u011f\u0131l\u0131m\u0131n yap\u0131s\u0131na Widmanstatten yap\u0131s\u0131 denir. A\u015f\u0131r\u0131 \u0131s\u0131t\u0131lm\u0131\u015f \u00f6tektoid \u00fcst\u00fc \u00e7elik so\u011futuldu\u011funda, sementit de tane s\u0131n\u0131r\u0131ndan taneye do\u011fru uzan\u0131r ve Widmanstatten yap\u0131s\u0131n\u0131 olu\u015fturur.<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

\u2166.Martenzit<\/h2>\n\n\n\n
\"\"<\/figure>\n\n\n\n

Alfa-Fe i\u00e7indeki a\u015f\u0131r\u0131 doymu\u015f kat\u0131 karbon \u00e7\u00f6zeltisine martensit denir. Martensit y\u00fcksek mukavemete ve sertli\u011fe sahiptir, ancak plastisitesi zay\u0131ft\u0131r, neredeyse s\u0131f\u0131rd\u0131r. M sembol\u00fc ile ifade edilen darbe y\u00fck\u00fcn\u00fc ta\u015f\u0131yamaz. Martenzit, a\u015f\u0131r\u0131 so\u011futulmu\u015f ostenitin h\u0131zl\u0131 so\u011fumas\u0131n\u0131n ve MS ve Mf noktalar\u0131 aras\u0131ndaki kesme modunun d\u00f6n\u00fc\u015f\u00fcm\u00fcn\u00fcn \u00fcr\u00fcn\u00fcd\u00fcr. Bu zamanda, karbon (ve ala\u015f\u0131m elementleri) zamanla yay\u0131lamaz, sadece gama-Fe'nin kafesinden (y\u00fcz merkezi) alfa-Fe'nin kafesine (g\u00f6vde merkezi), yani kat\u0131 \u00e7\u00f6zeltisine (ostenit) gama-Fe'deki karbondan alfa-Fe'deki kat\u0131 karbon \u00e7\u00f6zeltisine. Bu nedenle martensit d\u00f6n\u00fc\u015f\u00fcm\u00fc, martensitin lata martensit (d\u00fc\u015f\u00fck karbonlu) ve i\u011fneli martensite ayr\u0131labilen metalografik \u00f6zelliklerine dayanmaktad\u0131r.<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

a. \u00e7\u0131ta martenzit: <\/h3>\n\n\n\n

d\u00fc\u015f\u00fck karbonlu martensit olarak da bilinir. Kabaca ayn\u0131 boyuttaki ince martensit \u015feritleri, martensit demetleri veya martensit alanlar\u0131 olu\u015fturmak i\u00e7in paralel olarak hizalan\u0131r. alanlar ve alanlar aras\u0131ndaki oryantasyon fark\u0131 b\u00fcy\u00fckt\u00fcr ve ilkel bir ostenit tanesinde farkl\u0131 oryantasyonlara sahip birka\u00e7 alan olu\u015fturulabilir. \u00c7\u0131ta martenzit olu\u015fumunun y\u00fcksek s\u0131cakl\u0131\u011f\u0131ndan dolay\u0131, so\u011futma i\u015fleminde kendili\u011finden temperleme olgusu ka\u00e7\u0131n\u0131lmaz olarak meydana gelecek ve olu\u015fan martenzitte karb\u00fcrler \u00e7\u00f6kecek, bu nedenle erozyona ve kararmaya kar\u015f\u0131 savunmas\u0131zd\u0131r.<\/p>\n\n\n\n

 b. i\u011fneli martenzit:<\/h3>\n\n\n\n

ayr\u0131ca pul martensit veya y\u00fcksek karbonlu martensit olarak da bilinir, temel \u00f6zellikleri \u015funlard\u0131r: bir ostenit tanesinde olu\u015fan ilk martensit tabakas\u0131 nispeten b\u00fcy\u00fckt\u00fcr, genellikle t\u00fcm tah\u0131l boyunca, ostenit tanesi b\u00f6l\u00fcn\u00fcr, b\u00f6ylece daha sonra olu\u015fan martensitin boyutu s\u0131n\u0131rl\u0131d\u0131r , b\u00f6ylece pul martenzitin boyutu de\u011fi\u015fir, d\u00fczensiz da\u011f\u0131l\u0131m. Asik\u00fcler martenzit belirli bir y\u00f6nde olu\u015fur. Martenzit i\u011fnesinde orta \u00e7\u0131k\u0131nt\u0131 vard\u0131r. Karbon i\u00e7eri\u011fi ne kadar y\u00fcksekse, martenzit o kadar belirgindir. Ayn\u0131 zamanda martensit aras\u0131nda beyaz kal\u0131nt\u0131 \u00f6stenit bulunmaktad\u0131r.<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

 c. Su verme i\u015fleminden sonra olu\u015fan martensit ayr\u0131ca temperlemeden sonra \u00fc\u00e7 \u00f6zel metalografik yap\u0131 olu\u015fturabilir:<\/h3>\n\n\n\n

(i) Temperlenmi\u015f martenzit: <\/h4>\n\n\n\n

karbonun ge\u00e7i\u015f karb\u00fcrleri \u015feklinde \u00e7\u00f6z\u00fcld\u00fc\u011f\u00fc, temperlemenin ilk a\u015famas\u0131nda ayr\u0131\u015fan, s\u00f6nd\u00fcrme s\u0131ras\u0131nda olu\u015fan (tetragonal g\u00f6vde merkezinin kristal yap\u0131s\u0131 ile) levha martensit ve kat\u0131 i\u00e7inde da\u011f\u0131lm\u0131\u015f son derece ince ge\u00e7i\u015fli karb\u00fcr levhalar\u0131n kompoziti \u00e7\u00f6zelti matrisi (kristal yap\u0131s\u0131 v\u00fccut merkezli k\u00fcbe d\u00f6n\u00fc\u015fm\u00fc\u015ft\u00fcr) (matriks ile ara y\u00fcz tutarl\u0131 bir ara y\u00fczd\u00fcr) Faz yap\u0131s\u0131. Bu t\u00fcr bir yap\u0131, metalografik (optik) mikroskop alt\u0131nda maksimum b\u00fcy\u00fctmeye kadar b\u00fcy\u00fct\u00fcld\u00fc\u011f\u00fcnde bile i\u00e7 yap\u0131s\u0131n\u0131 ay\u0131rt edemez, sadece t\u00fcm yap\u0131s\u0131n\u0131n siyah i\u011fne oldu\u011funu g\u00f6rebilir (siyah i\u011fnenin \u015fekli temelde beyaz i\u011fnenin \u015fekli ile ayn\u0131d\u0131r). s\u00f6nd\u00fcrme s\u0131ras\u0131nda). Bu t\u00fcr siyah i\u011fneye \u201ctemperlenmi\u015f martenzit\u201d denir.<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

(ii) Temperlenmi\u015f troostit: <\/h4>\n\n\n\n

orta s\u0131cakl\u0131kta tavlanm\u0131\u015f, martenzitin i\u011fne \u015feklinin kademeli olarak kaybolmas\u0131yla karakterize edilen, ancak yine de belli belirsiz g\u00f6r\u00fcnen (krom i\u00e7eren ala\u015f\u0131ml\u0131 \u00e7elik, ala\u015f\u0131m ferrit yeniden kristalle\u015fme s\u0131cakl\u0131\u011f\u0131 daha y\u00fcksektir, bu nedenle hala i\u011fne \u015feklini korur), \u00e7\u00f6keltilmi\u015f karb\u00fcrler k\u00fc\u00e7\u00fck olan s\u00f6nd\u00fcr\u00fclm\u00fc\u015f martensit \u00fcr\u00fcn\u00fc , \u0131\u015f\u0131k mikroskobu alt\u0131nda ay\u0131rt edilmesi zor, karb\u00fcr partik\u00fclleri sadece elektron mikroskobu alt\u0131nda g\u00f6r\u00fclebilir, kutup Dokular\u0131n a\u015f\u0131nmas\u0131na ve kararmas\u0131na duyarl\u0131d\u0131r. Temperleme s\u0131cakl\u0131\u011f\u0131 daha y\u00fcksekse veya daha uzun s\u00fcre korunursa, i\u011fneler beyaz olacakt\u0131r. Bu s\u0131rada karb\u00fcrler i\u011fnelerin kenar\u0131nda yo\u011funla\u015facak ve \u00e7eli\u011fin sertli\u011fi biraz daha azalarak mukavemeti d\u00fc\u015fecektir.<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

(iii) tavlanm\u0131\u015f sorbit: <\/h4>\n\n\n\n

y\u00fcksek s\u0131cakl\u0131kta temperlenmi\u015f s\u00f6nd\u00fcr\u00fclm\u00fc\u015f martensit \u00fcr\u00fcn\u00fc. \u00d6zellikleri \u015funlard\u0131r: \u0131\u015f\u0131k mikroskobu alt\u0131nda a\u00e7\u0131k\u00e7a ay\u0131rt edilebilen sorbit matrisi \u00fczerinde ince taneli karb\u00fcrler da\u011f\u0131t\u0131l\u0131r. Ko\u015fullu yap\u0131 olarak da bilinen bu t\u00fcr yap\u0131, sa\u011flaml\u0131k ve dayan\u0131kl\u0131l\u0131\u011f\u0131n iyi bir kombinasyonuna sahiptir. Ferrit \u00fczerindeki ince karb\u00fcrler ne kadar ince olursa, sertlik ve mukavemet o kadar y\u00fcksek ve tokluk o kadar k\u00f6t\u00fc olur. aksine, sertlik ve mukavemet ne kadar d\u00fc\u015f\u00fckse ve tokluk o kadar y\u00fcksek olur.<\/p>\n\n\n\n

\u2167.Ledeburit<\/h2>\n\n\n\n
\"\"<\/figure>\n\n\n\n

FERROCARBON ala\u015f\u0131mlar\u0131ndaki \u00f6tektik kar\u0131\u015f\u0131mlar, yani k\u00fctle fraksiyonu 4.3% olan karbon (karbon i\u00e7eri\u011fi) s\u0131v\u0131 FERROCARBON ala\u015f\u0131mlar\u0131, ostenit ve sementitin mekanik kar\u0131\u015f\u0131mlar\u0131 s\u0131v\u0131dan ayn\u0131 anda 1480 santigrat derecede kristalle\u015fti\u011finde ledeburit olarak adland\u0131r\u0131l\u0131r. \u00d6stenit 727 C'de perlite d\u00f6n\u00fc\u015ft\u00fc\u011f\u00fc i\u00e7in oda s\u0131cakl\u0131\u011f\u0131nda ledeburit perlit ve sementitten olu\u015fur. 727 C'nin \u00fczerindeki ledeburiti ay\u0131rt etmek i\u00e7in y\u00fcksek s\u0131cakl\u0131k ledeburit (L d), 727 C'nin alt\u0131ndaki ledeburite ise d\u00fc\u015f\u00fck s\u0131cakl\u0131k ledeburit (L'd) denir. Ledeburitin \u00f6zellikleri, y\u00fcksek sertlik ve zay\u0131f plastisiteye sahip sementite benzer.<\/p>\n\n\n\n

\"\"<\/figure>\n<\/div>","protected":false},"excerpt":{"rendered":"

Modern materials can be divided into four categories: metals, polymers, ceramics and composite materials. Despite the rapid development of macromolecule materials, steel is still the most widely used and most important material in the current engineering technology. What factors determine the dominant position of steel materials? Now let’s introduce it in detail. Iron and steel…<\/p>","protected":false},"author":2,"featured_media":19470,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[79],"tags":[],"jetpack_featured_media_url":"https:\/\/www.meetyoucarbide.com\/wp-content\/uploads\/2019\/06\/1-6.png","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.meetyoucarbide.com\/tr\/wp-json\/wp\/v2\/posts\/3823"}],"collection":[{"href":"https:\/\/www.meetyoucarbide.com\/tr\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.meetyoucarbide.com\/tr\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.meetyoucarbide.com\/tr\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.meetyoucarbide.com\/tr\/wp-json\/wp\/v2\/comments?post=3823"}],"version-history":[{"count":0,"href":"https:\/\/www.meetyoucarbide.com\/tr\/wp-json\/wp\/v2\/posts\/3823\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.meetyoucarbide.com\/tr\/wp-json\/wp\/v2\/media\/19470"}],"wp:attachment":[{"href":"https:\/\/www.meetyoucarbide.com\/tr\/wp-json\/wp\/v2\/media?parent=3823"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.meetyoucarbide.com\/tr\/wp-json\/wp\/v2\/categories?post=3823"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.meetyoucarbide.com\/tr\/wp-json\/wp\/v2\/tags?post=3823"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}