![\"Demir.jpg\"](\"http:\/\/benga.pro\/wp-content\/uploads\/2019\/12\/demir.jpg\")
<\/p>\nM\u00fchendislikte kullan\u0131lan metallerin b\u00fcy\u00fck bir \u00e7o\u011funlu\u011fu saf halde de\u011fildir. Mekanik \u00f6zelliklerini mesela mukavemetini artt\u0131rmak i\u00e7in ba\u015fka metallerle belli oranlarda kar\u0131\u015ft\u0131r\u0131l\u0131r ve ala\u015f\u0131m olu\u015fturulur. Ala\u015f\u0131m, belirli bir metale belirli bir \u00f6zellik kazand\u0131rmak i\u00e7in ba\u015fka bir metal yada ametal ile kar\u0131\u015ft\u0131r\u0131larak elde edilen metal
\nkarakterli bir malzemedir. Ala\u015f\u0131m olu\u015fturmak i\u00e7in as\u0131l metal belli bir s\u0131cakl\u0131\u011fa kadar \u0131s\u0131t\u0131larak eritilir, di\u011fer elementlerle kar\u0131\u015ft\u0131r\u0131l\u0131r ve tekrar so\u011futulur. Bunun en g\u00fczel \u00f6rne\u011fi demirdir.<\/p>\n
Demir, yery\u00fcz\u00fcnde olduk\u00e7a yayg\u0131n bir element olmas\u0131na ra\u011fmen (yery\u00fcz\u00fcnde 4. yayg\u0131n elementtir ) saf haliyle mekanik \u00f6zelliklerinin d\u00fc\u015f\u00fckl\u00fc\u011f\u00fc nedeniyle pek de kullan\u0131\u015fl\u0131 olmayan bir metaldir. Ancak ba\u015fka elementlerle ala\u015f\u0131m\u0131 yap\u0131ld\u0131\u011f\u0131nda \u00e7ok kullan\u0131\u015fl\u0131 hale gelir. G\u00fcnl\u00fck hayat\u0131m\u0131zda duydu\u011fumuz “demir” kelimesi ile asl\u0131nda saf demir de\u011fil demir ile yap\u0131lan ala\u015f\u0131mlar kastedilmektedir.<\/p>\n
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Demir(Fe) ile karbon(C) birbirinden ayr\u0131lmaz bir ikilidir. Do\u011fada saf halde bulunan demirin i\u00e7ine az miktarda karbon eklenmesiyle mekanik \u00f6zellikleri son derece iyile\u015fmi\u015f bir ala\u015f\u0131m elde edilir. Demire eklenen karbonun miktar\u0131na g\u00f6re 3 durum olu\u015fur:<\/p>\n
![\"demircevheri.jpg\"](\"http:\/\/benga.pro\/wp-content\/uploads\/2019\/12\/demircevheri.jpg\")
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\u00c7elik yada d\u00f6kme demir \u00fcretiminin ilk a\u015famas\u0131 demir cevherinin i\u015flenmesidir. Demir cevheri, y\u00fcksek f\u0131r\u0131nlarda (Blast furnace) i\u015flenir ve pik demir (pig iron)<\/strong> \u00fcretilir. Pik demir bu haliyle kullan\u0131lmaya pek elveri\u015fli bir mamul olmay\u0131p \u00e7elik ve d\u00f6kme demir \u00fcretimi i\u00e7in kullan\u0131lan bir yar\u0131 mamuld\u00fcr. (“Pig” \u0130ngilizcede “domuz” demektir. Pik demirin \u00fcretiminde \u00fcr\u00fcn kal\u0131b\u0131n\u0131n domuza benzemesinden \u00f6t\u00fcr\u00fc bu isim kullan\u0131lm\u0131\u015ft\u0131r.) Pik demirin karbon oran\u0131 %4 civar\u0131ndad\u0131r. Pik demire ayn\u0131 zamanda font demir, ham demir<\/strong> de denir.<\/p>\n Elde edilen pik demirde e\u011fer mangan (Mn) fazla ise beyaz pik demir<\/strong>, silisyum(Si) fazla ise esmer pik demir<\/strong> olur. Beyaz pik demir, \u00e7elik \u00fcretimi i\u00e7in kullan\u0131l\u0131rken esmer pik demir, d\u00f6kme demir par\u00e7alar\u0131n \u00fcretimi i\u00e7in kullan\u0131l\u0131r.<\/p>\n Beyaz pik demir, f\u0131r\u0131nlarda, ark ocaklar\u0131nda i\u015flenerek karbon oran\u0131 d\u00fc\u015f\u00fcr\u00fcl\u00fcr ve \u00e7elik elde edilir. E\u011fer \u00e7eli\u011fin yap\u0131s\u0131nda sadece karbon varsa ala\u015f\u0131ms\u0131z \u00e7elik<\/strong> denir. E\u011fer \u00e7eli\u011fin yap\u0131s\u0131na mangan(Mn), krom (Cr), nikel (Ni), molibden (Mo) gibi elementler eklenmi\u015fse ala\u015f\u0131ml\u0131 \u00e7elik<\/strong> denir.<\/p>\n Ala\u015f\u0131ms\u0131z \u00e7elikler (Karbon \u00c7elikler)<\/strong> sahip olduklar\u0131 karbon miktar\u0131na g\u00f6re s\u0131n\u0131fland\u0131r\u0131l\u0131r. Buna g\u00f6re; D\u00fc\u015f\u00fck karbonlu \u00e7elikler<\/strong>in sertlik ve mukavemetleri d\u00fc\u015f\u00fckt\u00fcr, kolay i\u015flenir ve kolay kaynak yap\u0131labilir. Su verme ile sertle\u015ftirilemezler, sertlik ve mukavemetleri so\u011fuk \u015fekil verme ile artt\u0131r\u0131l\u0131r. Genel ama\u00e7lar i\u00e7in kullan\u0131lan en ucuz \u00e7eliklerdir. Bu \u00e7elikler yumu\u015fak \u00e7elik (mild steel)<\/strong> ad\u0131 da verilir. Otomobil g\u00f6vdesi, ince sac levha, \u00e7ivi, per\u00e7in, betonarme donat\u0131s\u0131, profil eleman malzemesi, profil eleman malzemesi \u00fcretiminde kullan\u0131l\u0131rlar.<\/p>\n Orta karbonlu \u00e7elikler<\/strong>in mukavemetleri ve tokluklar\u0131 y\u00fcksektir, plastik \u015fekil vererek i\u015flenebilirler. \u015eekil verildikten sonra su verme ile sertlik ve mukavemetleri birka\u00e7 kat artt\u0131r\u0131labilir. Bu \u00e7elikler genellikle yap\u0131larda, makina par\u00e7alar\u0131, buhar kazanlar\u0131, demiryolu raylar\u0131 gibi mukavemet istenen yerlerde kullan\u0131l\u0131rlar. Demiryolu raylar\u0131, tren ve tekerlekleri, dingil \u015faftlar\u0131 ve y\u00fcksek dayan\u0131ml\u0131 betonarme donat\u0131s\u0131 gibi sertlik ve y\u00fcksek dayan\u0131m gerektiren yerlerde kullan\u0131l\u0131r.<\/p>\n Y\u00fcksek karbonlu \u00e7elikler<\/strong>de sertlik ve mukavemet y\u00fcksek olmakla beraber, s\u00fcneklikleri ve tokluklar\u0131 d\u00fc\u015f\u00fckt\u00fcr, \u015fekil vermek zordur. Kaynak yetenekleri iyi de\u011fildir,kaynak s\u0131ras\u0131nda yerel sertle\u015fme ve gevrekle\u015fme olu\u015fur, \u00e7atlamalar meydana gelebilir.\u015eekil vermeden \u00f6nce 700\u00b0C civar\u0131nda uzun s\u00fcre tavlan\u0131rsa tabaka ve a\u011f \u015feklindeki demir karb\u00fcr faz\u0131 k\u00fcresel \u015fekil al\u0131r. Bu k\u00fcreselle\u015ftirme i\u015fleminden sonra yumu\u015fak ferrit faz\u0131 i\u00e7inde da\u011f\u0131lm\u0131\u015f k\u00fcresel demir karb\u00fcr tanelerinden olu\u015fan \u00e7elik kolay i\u015flenir ve daha sonra su verme ile sertle\u015ftirilir. Bu \u00e7elikler genellikle tak\u0131m, kal\u0131p, yay \u00e7elikleri olarak ve de\u011fi\u015fik \u00f6zellikli tellerin, sava\u015f ara\u00e7lar\u0131n\u0131n, keskin b\u0131\u00e7aklar\u0131n vb. yap\u0131m\u0131nda kullan\u0131l\u0131r.<\/p>\n Karbon\u2019un yan\u0131 s\u0131ra her ala\u015f\u0131ms\u0131z \u00e7eli\u011fe bir miktar silikon, mangan, fosfor ve k\u00fck\u00fcrt \u00fcretim s\u0131ras\u0131nda istem d\u0131\u015f\u0131 girer. Karbon oran\u0131 artt\u0131k\u00e7a mukavemet ve sertlik artar ancak esneklik, d\u00f6v\u00fclme, kaynaklanabilme ve i\u015flenebilme \u00f6zelikleri zarar g\u00f6r\u00fcr. Karbon oran\u0131n korozyona kar\u015f\u0131 dirence hi\u00e7bir etkisi yoktur.<\/p>\n \u00c7elikler \u00fcretilirken farkl\u0131 \u00f6zellikler ve kabiliyetler kazand\u0131rmak i\u00e7in karbonun yan\u0131nda ala\u015f\u0131m\u0131n i\u00e7ine mangan(Mn), krom (Cr), nikel (Ni), molibden (Mo) gibi elementler eklenir. Bu t\u00fcr \u00e7eliklere ala\u015f\u0131ml\u0131 \u00e7elik<\/strong> denir. Tahmin edilece\u011fi \u00fczere ala\u015f\u0131m\u0131n i\u00e7ine kat\u0131lar elementin t\u00fcr\u00fcne ve miktar\u0131na g\u00f6re \u00e7ok say\u0131da farkl\u0131 ala\u015f\u0131ml\u0131 \u00e7elik \u00fcretilir. Zaten D\u00fcnta \u00c7elik Derne\u011finin verilerine g\u00f6re g\u00fcn\u00fcm\u00fczde d\u00fcya \u00fczerinde 3500’den fazla \u00e7elik t\u00fcr\u00fc vard\u0131r ve bunlar\u0131n %75inden fazlas\u0131 son 25 y\u0131l i\u00e7inde \u00fcretilmi\u015ftir. Durum b\u00f6yle olunca ala\u015f\u0131ml\u0131 \u00e7elikleri s\u0131n\u0131fland\u0131rmak pek kolay olmamaktad\u0131r. Yine de kabaca \u015fu \u015fekilde s\u0131n\u0131fland\u0131r\u0131labilir:<\/p>\n Ala\u015f\u0131m elementleri \u00e7eli\u011fe a\u015fa\u011f\u0131daki \u00f6zellikleri katarlar. Bunlar;<\/p>\n Krom (Cr) :<\/strong> \u00c7eli\u011fin sertle\u015ftirilebilme \u00f6zelli\u011fini, \u00e7ekme mukavemetini ve korozyona dayan\u0131m\u0131n\u0131 artt\u0131r\u0131r. “Wrought Iron”<\/strong> ifadesi \u0130ngilizcede “Worked Iron”<\/strong> ifadesinin telaffuzunun de\u011fi\u015ftirilmi\u015f halidir. Yani \u00fczerinde \u00e7al\u0131\u015f\u0131lm\u0131\u015f demir anlam\u0131na gelmektedir. Bizim dilimize “d\u00f6vme demir” ifadesi Frans\u0131zcadan ge\u00e7mi\u015ftir. Frans\u0131zca’da d\u00f6vme demir “Fer Forge” dir ve zaten bazen bizde de d\u00f6vme demir yerine “ferforje”<\/strong> ifadesi de zaman zaman kullan\u0131l\u0131r. D\u00f6vme demir’i, d\u00f6v\u00fclebilir demir (Malleable Iron)<\/strong> ile kar\u0131\u015ft\u0131rmamak gerekir. D\u00f6v\u00fclebilir demir, bir d\u00f6kme demir \u00fcr\u00fcn\u00fcd\u00fcr ve karbon oran\u0131 %2-%3 civar\u0131ndad\u0131r . Bu \u00fcr\u00fcn de d\u00f6v\u00fclerek \u015fekil veremeye m\u00fcsaittir ama d\u00f6vme demir ile ayn\u0131 de\u011fildir. Bu konuya d\u00f6kme demirler b\u00f6l\u00fcm\u00fcnde ayr\u0131ca yine de\u011finece\u011fiz.<\/p>\n D\u00f6vme demir, g\u00fcn\u00fcm\u00fczde yukar\u0131da anlat\u0131lan s\u0131n\u0131fland\u0131rmada kendine uygun bir yer bulamam\u0131\u015ft\u0131r. Ancak ge\u00e7mi\u015fte, \u00e7elik ve d\u00f6k\u00fcm teknolojisinin bu kadar geli\u015fmedi\u011fi g\u00fcnlerde, pik demir (ham demir) \u00f6zel ocaklarda(Puddling f\u0131r\u0131n\u0131) karbonu d\u00fc\u015f\u00fcr\u00fclerek (max. %0,1) kal\u0131plan\u0131r ve so\u011futulurdu. \u0130\u00e7inde c\u00fcruf da bulundu\u011fundan tanecikli g\u00f6r\u00fcn\u00fcm\u00fc olurdu. Ortaya \u00e7\u0131kan bu \u00fcr\u00fcn \u0131s\u0131t\u0131larak \u00fczerinde \u00e7al\u0131\u015f\u0131lmaya ve \u015fekil vermeye son derece m\u00fcsait olurdu. Is\u0131t\u0131lm\u0131\u015f bu \u00fcr\u00fcn, \u00e7eki\u00e7le vurularak d\u00f6v\u00fcl\u00fcr ve arzu edilen \u015fekle getirilirdi. G\u00fcn\u00fcm\u00fczde ayn\u0131 i\u015flem, d\u00fc\u015f\u00fck karbonlu ala\u015f\u0131ms\u0131z \u00e7elik ile de rahatl\u0131kla yap\u0131labilmektedir.<\/p>\n \u00c7eli\u011fin binlerce t\u00fcr\u00fc oldu\u011funa g\u00f6re isimlendirilmesi ve numaraland\u0131r\u0131lmas\u0131 olduk\u00e7a g\u00fc\u00e7 olmu\u015ftur. Geli\u015fmi\u015f \u00fclkelerin bir \u00e7o\u011fu kendi standartlar\u0131n\u0131 ve isimlendirme y\u00f6ntemlerini geli\u015ftirmi\u015flerdir.<\/p>\n Amerika’da AISI, SAE<\/p>\n Almanya’da DIN, WNr<\/p>\n \u0130ngiltere’de BS<\/p>\n Rusya’da GOST<\/p>\n gibi… Zaten zaman zaman bir \u00e7elik \u00fcr\u00fcn\u00fcn\u00fcn teknik f\u00f6y\u00fcn\u00fc inceledi\u011fimizde malzeme standard\u0131 k\u0131sm\u0131nda epey bir standard\u0131n s\u0131raland\u0131\u011f\u0131n\u0131 g\u00f6r\u00fcr\u00fcz. \u00dcretici ister istemez, \u00fcretti\u011fi \u00fcr\u00fcn\u00fcn genel ge\u00e7er hangi standartlara uydu\u011funu belirtmek durumundad\u0131r. Ancak bu bilgilerin yan\u0131nda EN normundan \u00fclkemize getirilen TS EN 10027 standard\u0131na g\u00f6re isimlendirmesini de belirtmek durumundad\u0131r. Yani yukar\u0131daki t\u00fcm standartlar bir yana \u00fclkemizde ge\u00e7erli olan \u00e7elik isimlendirme ve numaraland\u0131rma standard\u0131 TS EN 10027’dir.<\/p>\n TS EN10027-1’de \u00e7eliklerin isimlendirilmesi (Mesela P195GH, S235 gibi) TS EN 10027-2 de numaraland\u0131r\u0131lmas\u0131 (Mesela 1. 0348 , 1.0425 gibi) a\u00e7\u0131klan\u0131r. \u0130lk olarak isimlendirmenin mant\u0131\u011f\u0131n\u0131 inceleyelim. Daha sonraki b\u00f6l\u00fcmde de numaraland\u0131rman\u0131n mant\u0131\u011f\u0131na bakal\u0131m.<\/p>\n \u0130nternet ortam\u0131nda \u00e7elik isimlendirmelerinin ve numaraland\u0131rmalar\u0131n\u0131n neye denk geldi\u011fini g\u00f6rebilece\u011finiz bir \u00e7ok site vard\u0131r. Bunlardan bir tanesi http:\/\/www.steelnumber.com\/<\/a> dur.<\/p>\n \u0130simlendirmenin mant\u0131\u011f\u0131n\u0131 anlamak ad\u0131na, tesisat sekt\u00f6r\u00fcnde yayg\u0131n kullan\u0131lan \u00e7eliklere bir g\u00f6z atal\u0131m. Hem ne t\u00fcr bir \u00e7elik oldu\u011funu hem de nas\u0131l isimlendirildi\u011fini anlamaya \u00e7al\u0131\u015fal\u0131m. Tabi bunun i\u00e7in TS EN 10027-1 standard\u0131n\u0131 \u00f6n\u00fcm\u00fcze a\u00e7mal\u0131, ilgili tablolara bakmal\u0131y\u0131z. (EN 10027-1 olarak bu ba\u011flant\u0131dan indirebilirsiniz.)<\/p>\n Bir \u00fcreticinin katalo\u011funa bakt\u0131\u011f\u0131m\u0131zda TS EN 10255 boru i\u00e7in S195, S235, S275, S355 ifadelerini g\u00f6r\u00fcr\u00fcz.<\/p>\n TS EN 10027-1 standard\u0131 Tablo-1 yard\u0131m\u0131yla, “S” ifadesinin “Structural”dan geldi\u011fini yani yap\u0131 \u00e7eli\u011fini ifade etti\u011fini anlar\u0131z. Daha sonra gelen 3 rakam, ilgili standarttaki en k\u00fc\u00e7\u00fck kal\u0131nl\u0131k durumunda \u00e7eli\u011fin akma dayan\u0131m\u0131n\u0131 ifade eder yani 195, 195MPa akma dayan\u0131m\u0131n oldu\u011funu anlat\u0131r. (1 MPa=1 N\/mm2). Demek ki S235 ba\u015fka bir kal\u0131nl\u0131k, S275 di\u011fer bir kal\u0131nl\u0131k de\u011feri i\u00e7in akma dayan\u0131mlar\u0131n\u0131 g\u00f6sterir. Zaten borular\u0131n da \u00e7aplar\u0131na g\u00f6re et kal\u0131nl\u0131klar\u0131 farkl\u0131l\u0131k g\u00f6stermektedir..<\/p>\n S195 ifadesinden sonra ba\u015fka ifadeler daha gelebilir ama \u00fcreticimiz katalo\u011funda bunlar\u0131 belirtmemi\u015f. Mesela S195K2 yazsayd\u0131, 195 MPa akma dayan\u0131ml\u0131, -20\u00baC de 40J darbe dayan\u0131m testi yap\u0131lm\u0131\u015f yap\u0131 \u00e7eli\u011fini anl\u0131yor olacakt\u0131k.<\/p>\n \u00dcreticinin katalo\u011funu inceledi\u011fimizde;<\/p>\n TS EN 10217-1 standard\u0131n\u0131n yan\u0131nda P195TR1, P235TR1, P265TR1 yazd\u0131\u011f\u0131n\u0131<\/p>\n TS EN 10217-2 standard\u0131n\u0131n yan\u0131nda P235GH, P265GH yazd\u0131\u011f\u0131n\u0131<\/p>\n TS EN 10217-3 standard\u0131n\u0131n yan\u0131nda P355 yazd\u0131\u011f\u0131n\u0131<\/p>\n g\u00f6r\u00fcr\u00fcz.<\/p>\n TS EN 10027-1 standard\u0131 Tablo-2 yard\u0131m\u0131yla, “P” ifadesinin “Pressure”dan geldi\u011fini yani bas\u0131n\u00e7l\u0131 olma durumunu ifade etti\u011fini anlar\u0131z.<\/p>\n P harfinden sonra gelen 3 rakam, yine en k\u00fc\u00e7\u00fck kal\u0131nl\u0131k i\u00e7in akma dayan\u0131m\u0131n\u0131 g\u00f6sterir. “T” harfi boru oldu\u011funu, “R” harfi oda s\u0131cakl\u0131\u011f\u0131nda kullan\u0131m\u0131 ifade eder. Son gelen “1” rakam\u0131 ilgili standard\u0131n (Burada EN 10217-1) 1. kategorisinde oldu\u011funu ifade eder.<\/p>\n P235GH ifadesinden, 235MPa akma dayan\u0131ml\u0131, verilenlerin d\u0131\u015f\u0131nda farkl\u0131 karakteristi\u011fi olan, y\u00fcksek s\u0131cakl\u0131kta bas\u0131n\u00e7l\u0131 kullan\u0131ma uygun \u00e7elik anla\u015f\u0131l\u0131r.<\/p>\n Buraya kadar \u00f6\u011frendiklerimizden asl\u0131nda bir ger\u00e7ek ortaya \u00e7\u0131k\u0131yor. Tesisat i\u015flerinde yayg\u0131n olarak kullan\u0131lan TS EN 10255 standard\u0131na uygun \u00e7elik borunun bir yap\u0131 \u00e7eli\u011fi oldu\u011fu g\u00f6r\u00fcn\u00fcyor. Boru olarak TS EN 10217-1\/2\/3 standartlar\u0131na y\u00f6nelinmesi gerekti\u011fi anla\u015f\u0131l\u0131yor.<\/p>\n Bu \u00fcr\u00fcnlerin kataloglar\u0131n\u0131 inceledi\u011fimizde S235JR, S235J0, S235J2, S275JR, S275J0, S275J2, S355JR, S355J0, S355J2, ifadelerine rastl\u0131yoruz. Yine TS EN 10027-1 standard\u0131 Tablo-1 yard\u0131m\u0131yla, “S” ifadesinin “Structural”dan geldi\u011fini yani yap\u0131 \u00e7eli\u011fini ifade etti\u011fini anl\u0131yoruz. Daha sonra gelen 3 rakam, ilgili standarttaki en k\u00fc\u00e7\u00fck kal\u0131nl\u0131k durumunda \u00e7eli\u011fin akma dayan\u0131m\u0131n\u0131 ifade ediyor yani 235, 235MPa akma dayan\u0131m\u0131n oldu\u011funu anlat\u0131yor. (1 MPa=1 N\/mm2).<\/p>\n JR ifadesi 20\u00baC s\u0131cakl\u0131kta 27J l\u00fck darbe testini ge\u00e7ti\u011fini ifade ediyor. J0 ifadesi 0\u00baC s\u0131cakl\u0131kta 27J l\u00fck darbe testini ge\u00e7ti\u011fini, J2 ifadesi -20\u00baC s\u0131cakl\u0131kta 27J l\u00fck darbe testini ge\u00e7ti\u011fini g\u00f6sterir.<\/p>\n Yukar\u0131da anlat\u0131lan \u00e7elik isimlendirmes algoritmas\u0131na ek olarak TS EN10027-2, \u00e7eliklerin numaraland\u0131r\u0131lmas\u0131 algoritmas\u0131n\u0131 da sunar.<\/p>\n Bir \u00e7eli\u011fin numaras\u0131 x.yyzz format\u0131ndad\u0131r.<\/p>\n Burada;<\/p>\n x, \u00e7elikler i\u00e7in 1’dir. Konumuz \u00e7elikler oldu\u011funa g\u00f6re her zaman 1 olacakt\u0131r.<\/p>\n yy, TS EN 10027-2 de belirtilen grup numaras\u0131n\u0131 ifade eder.<\/p>\n zz, sertifikaland\u0131rma kurulu\u015fu taraf\u0131ndan belirlenen s\u0131ral\u0131 bir say\u0131d\u0131r.<\/p>\n <\/p>\n TS EN 10027-2 de belirtilen gruplar \u015funlard\u0131r:<\/p>\n <\/p>\n \u00d6rne\u011fin, yukar\u0131da isimlendirmeyi anlat\u0131rken verdi\u011fimiz P195GH isimli \u00e7elik \u00f6rne\u011fini inceleyelim. Bu \u00e7eli\u011fin numaras\u0131 1.0348 ‘dir. http:\/\/www.steelnumber.com\/<\/a> sitesinden 1.0348’i inceleyelim.<\/p>\n G\u00f6r\u00fcld\u00fc\u011f\u00fc gibi ilgili \u00e7eli\u011fin kimyasal yap\u0131s\u0131 ve mekanik \u00f6zelliklerine ula\u015fm\u0131\u015f oluyoruz.<\/p>\n <\/p>\n <\/p>\n <\/p>\n \u00c7elikler, yap\u0131s\u0131ndan se\u00e7imine kadar \u00e7ok derin bir konudur. Burada demir ve \u00e7elik aras\u0131ndaki fark\u0131n yan\u0131 s\u0131ra \u00e7eli\u011fin kendi i\u00e7inde nas\u0131l s\u0131n\u0131fland\u0131r\u0131ld\u0131\u011f\u0131n\u0131 anlatmaya ve temel bilgileri vermeye \u00e7al\u0131\u015ft\u0131k. Bir sonraki yaz\u0131m\u0131zda d\u00f6kme demirler konusuna girece\u011fiz.<\/p>\n <\/p>\n Kaynaklar:<\/strong><\/p>\n http:\/\/www.egevizyonakademi.com.tr\/haber\/27\/malzeme-secimi-celikler\/<\/p>\n![\"pigiron.jpg\"](\"http:\/\/benga.pro\/wp-content\/uploads\/2019\/12\/pigiron.jpg\")
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\n3. \u00c7elik (Steel)<\/h4>\n
![\"\u00e7elik.jpg\"](\"http:\/\/benga.pro\/wp-content\/uploads\/2019\/12\/c3a7elik.jpg\")
<\/p>\n3.1 Ala\u015f\u0131ms\u0131z \u00c7elik (Non-Alloy Steel)<\/h4>\n
\n% 0,25 \u2019e kadar karbon i\u00e7eren \u00e7eliklere d\u00fc\u015f\u00fck karbonlu \u00e7elikler<\/strong>,
\n% 0,25-0,55 aras\u0131 karbon i\u00e7eren \u00e7eliklere orta karbonlu \u00e7elikler<\/strong>,
\n% 0,55\u2019in \u00fczerinde karbon i\u00e7eren \u00e7eliklere y\u00fcksek karbonlu \u00e7elikler<\/strong> denir<\/p>\n3.2 Ala\u015f\u0131ml\u0131 \u00c7elik (Alloy Steel)<\/h4>\n
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\nNikel (Ni) :<\/strong> \u00c7eli\u011fin \u00e7ekme mukavemetini, yorulma (fatigue) direncini, toklu\u011funu ve korozyona dayan\u0131m\u0131n\u0131 artt\u0131r\u0131r.
\nMolibden (Mo) :<\/strong> \u00c7eli\u011fin sertle\u015ftirilebilme \u00f6zelli\u011fini artt\u0131rt\u0131r.
\nFosfor (P):<\/strong> \u00c7eli\u011fin \u00e7ekme mukavemetini geli\u015ftirir ancak toklu\u011fu azalt\u0131r.
\nSilisyum (Si):<\/strong> \u0130nce taneli \u00e7elik yap\u0131s\u0131na elverir, sertle\u015ftirilebilme \u00f6zelli\u011fini, \u00e7ekme mukavemetini ve elektriksel \u00f6zelliklerini geli\u015ftirir.
\nWolfram (Tungsten) (W) :<\/strong>Sertli\u011fin \u00e7ok fazla y\u00fcksek de\u011ferlere ula\u015fabilmesini sa\u011flar ve a\u015f\u0131nmaya direnci artt\u0131r\u0131r. Ancak bu element \u00e7ok pahal\u0131d\u0131r.
\nVanadyum (V):<\/strong> \u00c7ekme mukavemetini, yorulma (fatigue) direncini ve \u015fok darbelere direnci artt\u0131r\u0131r.
\nMangan (Mn) :<\/strong> \u00c7eli\u011fin \u00e7ekme mukavemetini ve \u015fok darbelere direncini artt\u0131r\u0131r.
\nKur\u015fun (Pb) :<\/strong> \u0130\u015flenebilirli\u011fi artt\u0131r\u0131r.
\nBak\u0131r (Cu) :<\/strong> Korozyona dayan\u0131m\u0131n\u0131 artt\u0131r\u0131r.
\nAl\u00fcminyum (Al):<\/strong> \u0130nce taneli \u00e7elik yap\u0131s\u0131na elverir. \u00c7elik i\u00e7erisindeki \u00e7\u00f6z\u00fcnm\u00fc\u015f oksijeni giderir.<\/p>\n
\n4. D\u00f6vme Demir (Wrought Iron)<\/h4>\n
![\"wroughtiron.jpg\"](\"http:\/\/benga.pro\/wp-content\/uploads\/2019\/12\/wroughtiron.jpg\")
<\/p>\n
\n5. \u00c7eliklerin isimlendirilmesi ve numaraland\u0131r\u0131lmas\u0131<\/h4>\n
5.1. \u00c7eliklerin \u0130simlendirilmesi<\/h4>\n
\n
![\"EN](\"http:\/\/benga.pro\/wp-content\/uploads\/2019\/12\/en-10027-1-table-1.jpg\")
<\/p>\n\n
![\"EN](\"http:\/\/benga.pro\/wp-content\/uploads\/2019\/12\/en-10027-1-table-2.jpg\")
<\/p>\n\n
5.2. \u00c7eliklerin Numaraland\u0131r\u0131lmas\u0131<\/h4>\n
\n\n
\n Grup Kodu<\/th>\n Tip<\/th>\n<\/tr>\n \n Ala\u015f\u0131ms\u0131z \u00c7elikler<\/b><\/th>\n<\/tr>\n \n 00 & 90<\/td>\n Temel \u00c7elikler<\/td>\n<\/tr>\n \n 0x & 9x<\/td>\n Kalite \u00e7elikler<\/td>\n<\/tr>\n \n 1x<\/td>\n \u00d6zel \u00c7elikler<\/td>\n<\/tr>\n \n Alloy steels<\/b><\/th>\n<\/tr>\n \n 2x<\/td>\n Tak\u0131m \u00c7elikleri<\/td>\n<\/tr>\n \n 3x<\/td>\n Muhtelif \u00c7elikler<\/td>\n<\/tr>\n \n 4x<\/td>\n Paslanmaz ve \u0131s\u0131ya dayan\u0131kl\u0131 \u00c7elikler<\/td>\n<\/tr>\n \n 5x \u2013 8x<\/td>\n Yap\u0131 – Bas\u0131n\u00e7l\u0131 Kap – M\u00fchendislik \u00c7elikleri<\/td>\n<\/tr>\n \n 08 & 98<\/td>\n \u00d6zel fiziksel karakteristikler<\/td>\n<\/tr>\n \n 09 & 99<\/td>\n Di\u011fer kullan\u0131m \u00c7elikleri<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n ![\"P195GH.jpg\"](\"http:\/\/benga.pro\/wp-content\/uploads\/2019\/12\/p195gh.jpg\")
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