[go: up one dir, main page]

TR201921217A2 - High strength, low alloy steel composition - Google Patents

High strength, low alloy steel composition

Info

Publication number
TR201921217A2
TR201921217A2 TR2019/21217A TR201921217A TR201921217A2 TR 201921217 A2 TR201921217 A2 TR 201921217A2 TR 2019/21217 A TR2019/21217 A TR 2019/21217A TR 201921217 A TR201921217 A TR 201921217A TR 201921217 A2 TR201921217 A2 TR 201921217A2
Authority
TR
Turkey
Prior art keywords
max
micro
steel composition
weight
alloyed steel
Prior art date
Application number
TR2019/21217A
Other languages
Turkish (tr)
Inventor
Çulha Osman
Eyçi̇n Fulya
Original Assignee
Tirsan Kardan Sanayi Ve Ticaret Anonim Sirketi
Ti̇rsan Kardan Sanayi̇ Ve Ti̇caret Anoni̇m Şi̇rketi̇
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Tirsan Kardan Sanayi Ve Ticaret Anonim Sirketi, Ti̇rsan Kardan Sanayi̇ Ve Ti̇caret Anoni̇m Şi̇rketi̇ filed Critical Tirsan Kardan Sanayi Ve Ticaret Anonim Sirketi
Priority to TR2019/21217A priority Critical patent/TR201921217A2/en
Priority to PCT/TR2020/051351 priority patent/WO2021133343A1/en
Publication of TR201921217A2 publication Critical patent/TR201921217A2/en

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/14—Ferrous alloys, e.g. steel alloys containing titanium or zirconium
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21J—FORGING; HAMMERING; PRESSING METAL; RIVETING; FORGE FURNACES
    • B21J1/00—Preparing metal stock or similar ancillary operations prior, during or post forging, e.g. heating or cooling
    • B21J1/06—Heating or cooling methods or arrangements specially adapted for performing forging or pressing operations
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/005—Modifying the physical properties by deformation combined with, or followed by, heat treatment of ferrous alloys
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0247—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/06—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires
    • C21D8/065—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires of ferrous alloys
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/08—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for tubular bodies or pipes
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/001—Ferrous alloys, e.g. steel alloys containing N
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/08—Ferrous alloys, e.g. steel alloys containing nickel
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/12—Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium, or niobium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/16—Ferrous alloys, e.g. steel alloys containing copper
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/002—Bainite
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/004—Dispersions; Precipitations
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/005—Ferrite
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/009—Pearlite

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Heat Treatment Of Steel (AREA)
  • Heat Treatment Of Sheet Steel (AREA)
  • Laminated Bodies (AREA)

Abstract

Buluş özellikle, 500-600 MPa akma mukavemeti, 700-750 MPa çekme mukavemetine sahip, ağırlıkça %0,05-0,15 oranında karbon (C), ağırlıkça maks. %0,005 oranında bor (B), ağırlıkça maks. %0,007 oranında azot (N), ağırlıkça maks. %0,25 oranında silisyum (Si), ağırlıkça maks. %0,9 oranında mangan (Mn), ağırlıkça maks. %0,4 oranında krom (Cr), ağırlıkça maks. %0,1 oranında molibden (Mo), ağırlıkça maks. %0,2 nikel (Ni), ağırlıkça maks. %0,1 oranında vanadyum (V), ağırlıkça %0,05-2 oranında titanyum (Ti), ağırlıkça maks. %0,3 oranında fosfor (P), ağırlıkça maks. % 0,3 oranında kükürt (S) ve ağırlıkça maks. %0,25 oranında bakır (Cu) içeren mikro alaşımlı çelik kompozisyonu ile ilgilidir.In particular, the invention has a yield strength of 500-600 MPa, a tensile strength of 700-750 MPa, carbon (C) at the rate of 0.05-0.15% by weight, max. 0.005% boron (B), max. 0.007% nitrogen (N), max. 0.25% silicon (Si), max. 0.9% manganese (Mn), max. 0.4% chromium (Cr), max. 0.1% molybdenum (Mo), max. 0.2% nickel (Ni), max. 0.1% vanadium (V), 0.05-2% by weight titanium (Ti), max. 0.3% phosphorus (P), max. 0.3% sulfur (S) and max. It is related to the composition of micro-alloyed steel containing 0.25% copper (Cu).

Description

TARIFNAME Yüksek mukavemetli, düsük alasimli çelik kompozisyonu Teknik Alan Bulus, sicak dövme proseslerinin uygulanabildigi tüm alanlarda kullanilmak üzere gelistirilen yüksek mukavemetli, düsük alasimli çelik kompozisyonu ile ilgilidir. agirlikça maks. %000? oraninda azot (N), agirlikça maks. %025 oraninda silisyum (Si), agirlikça maks. %09 oraninda mangan (Mn), agirlikça maks. %0,4 oraninda krom (Cr), agirlikça maks. %0,1 oraninda molibden (Mo), agirlikça maks. %0,2 nikel (Ni), agirlikça maks. %0,1 oraninda vanadyum (V), agirlikça %0,05-2 oraninda titanyum (Ti), agirlikça maks. %0,3 oraninda fosfor (P), agirlikça maks. % 0,3 oraninda kükürt (S) ve agirlikça maks. Teknigin Bilinen Durumu Mikro alasimli çelikler, dünya çelik üretiminin yaklasik %12'sini olusturarak çelik türleri arasinda önemli bir yere sahiptir. Dünyanin birçok bölgesinde tüm büyük çelik pazarlarinda kullanilmakta olan bu çelikler, otomotiv, gaz ve petrol boru hatlari, insaat, ulasim (transport) endüstrilerinde önemli rol oynamaktadir. Mikro alasimli çeliklerin spesifik gelisim yönlerini, az perlitli ve perlitsiz çelikler olusturmaktadir. Karbon oraninin bariz sekilde düsürülmesi ile sekil verilebilirlik, tokluk, kaynak edilebilirlik gibi özellikler önemli oranda yükseltilmektedir. Bahsedilen bu özellikler genellikle sekil vermek suretiyle yüksek mukavemetli ve hafif parçalarin üretiminde istenilmektedir. Düsük karbon oranina ragmen bu çeliklerde, mikro alasim elementleri olan alüminyum (AI), niobyum (Nb), titanyum (Ti), vanadyum'un (V) tane inceltici ve sertlestirici etkileri ile kontrollü haddelemeyle akma siniri ancak 500 N/mm2 ye ulasabilmektedir. Mikro alasimli çeliklerde, alasim elementi olarak kullanilan niobyum (Nb), titanyum (Ti), vanadyum (V) ve alüminyum (AI), malzemenin mekanik özelliklere dogrudan önemli etkileri bulunmakta olup, karbür, nitrür veya karbonitrür olusturmaktadir. Mikro alasim elementlerinin olusturdugu karbür, nitrür ve karbonitrürler, sicak sekillendirme islemleri sirasinda çözünme sicakliklarinin üzerine çikilmadigi takdirde Östenit fazi içerisinde çözünmeden kalmaktadir. Çözünmeyen bu sert yapilar östenit tane büyümesini engelleyerek hem küçük taneli bir çelik yapisi elde edilmesini hem de malzemenin toklugunun artmasini saglamaktadir. Mevcut teknikte yüksek mukavemet elde etmek amaci ile alasimdaki karbon miktarinin arttirilmasi veya mikro alasim elementlerinin tane inceltme özelliginden faydalanilmaktadir. Yüksek karbonlu çelik alasimi, sicak dövme isleminden sonra isil isleme tabi tutulmakta ve mukavemet arttirmak üzere ikincil bir islem gereksinim duyulmaktadir. Diger yandan bilinen teknikte mikro alasimli çelikler, dövülmüs malzemenin mukavemetini isil islemli yüksek karbonlu alasim kadar arttiramamaktadir. Yüksek karbonlu C45E standardindaki çelik alasiminin akma mukavemeti 500 MPa, çekme mukavemeti 750-850 MPa iken, mikro alasimli çelikte ise akma mukavemeti 435 MPa ve çekme mukavemeti 580-780 MPa arasindadir. Bahsedildigi üzere yüksek karbonlu çeligin ikincil islemle maliyetli bir uygulama sonucu mukavemet arttirilmasi ve mikro alasimli çelikte akma mukavemetinin düsük olmasi, yeni bir çelik alasimi gelistirilmesi ihtiyacini ortaya koymaktadir. Literatürde konu ile ilgili olarak CA2666677A1 numarali patent basvurusuna rastlanilmistir. Bulus, çelik ve yüksek mukavemetli, bölünerek kirilabilen makine parçalarinin üretim prosesi ile ilgilidir. Bulusa konu çeligin kimyasal kompozisyonu agirlikça %0,40-0,60 karbon (C), (Ni), maks. %02 molibden (M0), maks. %0,050 niobyum (Nb), maks. %0,3 vanadyum (V), elementlerle dengede demir (Fe) ve safsizliklardan olusmaktadir. maks. %O,5 alüminyum (AI), maks. %0,03 azot (N), vanadyum ve demir içeren bir çelik kompozisyonu ile ilgilidir. Söz konusu basvurularda görüldügü üzere, bilinen teknikte birçok çelik kompozisyonu bulunmaktadir. Ancak, yüksek mukavemetli ve yüksek akma mukavemetine sahip mikro alasimli çelik alasimlara ihtiyaç gün geçtikçe artmaktadir. Sonuç olarak yukarida bahsedilen olumsuzluklardan ve eksikliklerden dolayi, ilgili teknik alanda bir yenilik yapma ihtiyaci ortaya çikmistir. Bulusun Amaci Mevcut bulus, yukarida bahsedilen gereksinimleri karsilayan, tüm dezavantajlari ortadan kaldiran ve ilave bazi avantajlar getiren, yüksek mukavemetli, düsük alasimli çelik kompozisyonu ile ilgilidir. Bulusun ana amaci, uzun ürün hammaddesi olarak sicak dövme proseslerinde kullanilabilecek nitelikte bir mikro alasimli çelik kompozisyonu ortaya koymaktir. Bulusun amaci, yüksek mukavemetli düsük alasimli bir çelik kompozisyonu ortaya koymaktir. Bulusun amaci, kontrollü dövme sonrasinda akma mukavemeti 500-600 Mpa, çekme elde etmektir. Bulusun amaci, karbür yapici olarak titanyum ve vanadyumun birlikte kullanilmasi sayesinde, tane incelterek mukavemet arttirma mekanizmasini aktive etmek ve toklukla birlikte mukavemet artisi saglamaktir. Bulusun amaci, dövme sicakligi ve dövme sonrasi sogutma ortami için gerekli olan birincil 1500 saniye, isi transfer katsayisinin 40-80 W/mZK olmasi sayesinde, tane inceltici elementlerin etkisini ortaya koyabilmesini saglamaktir. Bulusun amaci, çelik kompozisyonu içerisinde bor elementi kullanilmasi ile sertligi arttirmaktir. Bor elementi karbon gibi kristal yapiya ara yer atomu olarak yerlesmekte olup, çözünürlügünün yüksek olmasi sebebi ile de kristalde distorsiyon yaratarak sertligi arttirmaktadir. Bulusun bir amaci, C, N, B gibi ara yer atomlari ile Mn, Si, Ni, V ve Ti gibi elementlerin nitrür, karbür ve karbonitrür yapma özelliklerinden faydalanilarak çelik kompozisyonunun mekanik özelliklerini gelistirilmektir. Yukarida anlatilan amaçlarin yerine getirilmesi için bulus, mikro alasimli çelik kompozisyonu bor (B), agirlikça maks. o/00,007' oraninda azot (N), agirlikça maks. %025 oraninda silisyum (Si), agirlikça maks. %0,9 oraninda mangan (Mn), agirlikça maks. %0,4 oraninda krom (Cr), agirlikça maks. %0,1 oraninda molibden (M0), agirlikça maks. %0,2 nikel (Ni), agirlikça maks. %0,1 oraninda vanadyum (V), agirlikça %0,05-2 oraninda titanyum (Ti), agirlikça maks. %0,3 oraninda fosfor (P), agirlikça maks. % 0,3 oraninda kükürt (S) ve agirlikça maks. Bulusun amaçlarini gerçeklestirmek üzere, 0 mikro alasimlama ile üretilen çelik kompozisyonun sürekli döküm yöntemi ile kütük formunda elde edilmesi, o üretilen kütüklerin sicak haddeleme ile yuvarlak uzun grubunda silindirik yari mamul haline getirilmesi, . uzun yari mamüllerin kontrollü sicak dövme ve sogutma asamalarindan geçirilmesiyle çökelti olusmasi, islem adimlarini içeren mikro alasimli çelik kompozisyon üretim yöntemi olup, özelligi; . bahsedilen dövme sicakliginin 950-1150 °C'de, dövme sonrasi birincil sogutmanin saniye süreyle isi katsayisi 40-80 W/mzK olacak atmosfer kosullarinda olmaktadir. Bulusun yapisal ve karakteristik özellikleri ve tüm avantajlari asagida verilen detayli açiklama sayesinde daha net olarak anlasilacaktir ve bu nedenle degerlendirmenin de bu detayli açiklama göz önüne alinarak yapilmasi gerekmektedir. Bulusun Detayli Açiklamasi Bu detayli açiklamada, yüksek mukavemetli, düsük alasimli çelik kompozisyonu, sadece konunun daha iyi anlasilmasina yönelik olarak ve hiçbir sinirlayioi etki olusturmayacak sekilde açiklanmaktadir. Bulus, sicak dövme proseslerinin uygulanabildigi tüm alanlarda kullanilmak üzere gelistirilen mikro alasimli çelik kompozisyonu olup, özelligi; agirlikça %0,05-0,15 oraninda karbon (C), agirlikça maks. %0,005 oraninda bor (B), agirlikça maks. %000? oraninda azot (N), agirlikça maks. %0,25 oraninda silisyum (Si), agirlikça maks. %0,9 oraninda mangan (lVIn), agirlikça maks. %0,4 oraninda krom (Cr), agirlikça maks. %0,1 oraninda molibden (Mo), agirlikça maks. %02 nikel (Ni), agirlikça maks. %0,1 oraninda vanadyum (V), agirlikça 0,3 oraninda kükürt (S) ve agirlikça maks. %025 oraninda bakir (Cu) içermesidir. Bulusa konu mikro alasimli çelik kompozi'syonunun formüi'asvonu; Içerik Agirlikça Kullanilabilir Miktar (%) Karbon (C) 0,05-0,15 Azot (N) s 0,007 Silisyum (Si) 5 0,25 Molibden (M0) 5 0,1 Vanadyum (V) 5 0,1 Titanyum (Ti) 0,05-0,2 Fosfor (P) 5 0,3 Bakir (Cu) 5 0,25 Bulusa konu mikro alasimli çelik kompozisyonunu elde etmek üzere, ilk olarak alasim elementleri belirlenmektedir. Çelik kompozisyonu içerisindeki alasim elementi miktari ve çesitliligi, mekanik özelliklerin gelistirilmesinde önemli parametrelerdir. Farkli mukavemet arttirma mekanizmalarinin birlikte ortaya çikmasini saglamak üzere, C, N, B gibi ara yer atomlari ile Mn, Si, Ni, V ve Ti gibi elementlerin nitrür, karbür ve karbonitrür yapma özelliklerinden faydalanilmaktadir. Diger yandan TTT (izotermal dönüsüm diyagrami) ve CCT (sürekli soguma dönüsüm diyagrami) diyagramlarinin alasim elementine göre degismesi özelliginden faydalanilarak da ince taneli ve çok fazli mikro yapi elde edilmektedir. Ikinci olarak sicak dövme metodolojisi olusturulmaktadir. Sicak dövme islemindeki sicaklik ve deformasyon oranlari özgün alasima göre yeniden düzenlenmektedir. Son olarak da sogutma islemi uygulamaktir. TTT (izotermal dönüsüm diyagrami) ve CCT (sürekli soguma dönüsüm diyagrami) diyagramlarina göre hedef mikro yapi (ferrit, perlit, beynit) için sogutma rejimi belirlenmektedir. Demir-karbon faz diyagraminda martenzit ve beynit dönüsüm alasimin sertlesme mekanizmasinda önemli bir yere sahiptir. Ancak endüstriyel çelik üretiminde proses kosullarindan dolayi soguma hizlari denge kosullarina göre oldukça yüksektir. Soguma hizinin artmasi ile birlikte faz dönüsümlerinin belirlenmesinde kullanilan demir-karbon faz diyagrami kullanilmamaktadir. Bunun en önemli nedeni söz konusu diyagramin çok yavas soguma kosullarinda olusturulmasidir. Bu nedenle yüksek soguma hizlarinda TTT adi verilen ve faz dönüsümünün sicakliga ve zamana bagli olarak degisimini gösteren diyagramlari kullanilmaktadir. Hizli sogutulan çeliklerde östenitin ne zaman dönüsüme baslayacagi, dönüsümün ne kadar süre sonunda tamamlanacagi ve sonuçta hangi ürünlerin olusacagi hususlari izotermal dönüsüm diyagramlari yardimiyla belirlenmektedir. Dolayisiyla, TTT diyagramlari sicakligin ve zamanin fonksiyonu olarak alasim içerisinde asiri soguma kosullarinda bagli olarak olusacak faz dönüsümlerinin belirlenmesinde tercih edilmektedir. Dönüsme reaksiyonunda zaman ve sicaklik etkilerini ayri ayri görebilmek amaciyla dönüsme egrisini degistirmek gerekmektedir. Bu durumu gösteren egrilere de sürekli soguma dönüsüm egrileri (CCT) adi verilmektedir. Sürekli sogumayi kapsayan bütün isil islemler için CCT diyagramlari kullanilabilmektedir. CCT diyagramlarinin ana amaci hangi yapi elemanlarinin elde edilecegi ve buna karsilik hangi sertliklerin elde edilebileceginin soguma egrisinden faydalanarak önceden bilinmesidir. Bu diyagramlar, hem sicakligin sabit tutuldugu izotermal isil islemler hem de sürekli sogumadaki dönüsüm sonrasinda elde edilecek son mikroyapilarin içerdigi faz veya fazlarin belirlenmesine imkan saglamaktadir. Bulus konusu çelik kompozisyonu içerisinde bor elementi kullanilmasi ile sertlik artmaktadir. Bor elementi karbon gibi kristal yapiya ara yer atomu olarak yerlesmekte olup, çözünürlügünün yüksek olmasi sebebi ile de kristalde distorsiyon yaratarak sertligi arttirmaktadir. Karbür yapici olarak titanyum ve vanadyumun birlikte kullanilmasi sayesinde de tane incelterek mukavemet arttirma mekanizmasi aktive edilmekte ve toklukla birlikte mukavemet artisi saglanmaktadir. Bulus konusu mikro alasimli celik kompozisyonunu Üretim yöntemi; i Mikro alasimlama ile üretilen çelik kompozisyonu sirasiyla, elektrik ark ocagi, pota ocagi, vakum ocagi ve tundish daldirma kapali seramik tüp kullanilarak sürekli döküm yöntemi ile kütük formunda elde edilir, i Üretilen kütükler sicak haddeleme ile yuvarlak uzun grubunda silindirik yari mamul haline getirilir, 0 Uzun yari mamüller kontrollü sicak dövme ve sogutma asamalarindan geçirilir, o Olusan çökelti sertlesme mekanizmasi ile istenilen mekanik degerlerde çelik alasim Bulusa konu üretim yönteminde kullanilan sicak dövme sicakligi 950-1150 °C, dövme gerçeklestirilmektedir. C-N çökeltileri olusmaktadir. Bulusa konu mikro alasimli Çelik kompozisyonun mekanik özellikleri; . Çekme mukavemeti 700-750 MPa, . Sertligi 210-230 HV, o Esdeger karbon degeri O,43-0,45 Ceq seklindedir. Bulusun tercih edilen yapilanmasinda bahsedilen uzun ürün, yuvarlak, kare, yuvarlak köseli kare, lama, genis Iamalar vs. tüm çelik ürünleri kapsamaktadir. TR TR DESCRIPTION High strength, low alloy steel composition Technical Field The invention relates to the high strength, low alloy steel composition developed for use in all areas where hot forging processes can be applied. weight max. 000%? rate of nitrogen (N), by weight max. 025% silicon (Si), by weight max. 09% manganese (Mn), max. 0.4% chromium (Cr), by weight max. 0.1% molybdenum (Mo), max. 0.2% nickel (Ni), max. by weight. 0.1% vanadium (V), 0.05-2 wt% titanium (Ti), max. 0.3% phosphorus (P), by weight max. 0.3% sulfur (S) and max. State of the Art Micro-alloyed steels have an important place among steel types, constituting approximately 12% of world steel production. These steels, which are used in all major steel markets in many regions of the world, play an important role in the automotive, gas and oil pipelines, construction and transportation industries. The specific development directions of micro-alloyed steels are steels with low pearlite and without pearlite. By significantly reducing the carbon content, properties such as formability, toughness and weldability are significantly increased. These features are generally desired in the production of high-strength and lightweight parts by shaping. Despite the low carbon content, the flow limit of these steels can only reach 500 N/mm2 with controlled rolling due to the grain thinning and hardening effects of the micro alloying elements aluminum (Al), niobium (Nb), titanium (Ti) and vanadium (V). In micro-alloyed steels, niobium (Nb), titanium (Ti), vanadium (V) and aluminum (Al), used as alloying elements, have significant direct effects on the mechanical properties of the material and form carbide, nitride or carbonitride. Carbides, nitrides and carbonitrides formed by microalloy elements remain undissolved in the austenite phase unless their dissolution temperatures are exceeded during hot forming processes. These hard, insoluble structures prevent austenite grain growth, allowing a small-grained steel structure to be obtained and increasing the toughness of the material. In the current technique, in order to obtain high strength, increasing the amount of carbon in the alloy or the grain refining feature of microalloy elements is used. High carbon steel alloy is subjected to heat treatment after hot forging and a secondary process is required to increase strength. On the other hand, in the known art, micro-alloyed steels cannot increase the strength of the forged material as much as heat-treated high carbon alloys. While the yield strength of the high carbon C45E standard steel alloy is 500 MPa and the tensile strength is 750-850 MPa, the yield strength of micro-alloyed steel is 435 MPa and the tensile strength is between 580-780 MPa. As mentioned, increasing the strength of high carbon steel as a result of costly secondary processing and the low yield strength of micro-alloyed steel reveal the need to develop a new steel alloy. A patent application numbered CA2666677A1 was found in the literature regarding the subject. The invention is related to the production process of steel and high-strength, breakable machine parts. The chemical composition of the steel subject to the invention is 0.40-0.60% carbon (C), (Ni) by weight, max. 02% molybdenum (M0), max. 0.050% niobium (Nb), max. It consists of 0.3% vanadium (V), iron (Fe) in balance with elements and impurities. max. 0.5% aluminum (AI), max. It relates to a steel composition containing 0.03% nitrogen (N), vanadium and iron. As can be seen in the applications in question, there are many steel compositions in the known art. However, the need for microalloyed steel alloys with high strength and high yield strength is increasing day by day. As a result, due to the negativities and deficiencies mentioned above, the need for innovation in the relevant technical field has emerged. Purpose of the Invention The present invention relates to a high-strength, low-alloy steel composition that meets the above-mentioned requirements, eliminates all disadvantages and brings some additional advantages. The main purpose of the invention is to produce a micro-alloyed steel composition that can be used in hot forging processes as a long product raw material. The aim of the invention is to produce a high-strength low-alloy steel composition. The aim of the invention is to obtain a yield strength and tensile strength of 500-600 Mpa after controlled forging. The purpose of the invention is to activate the strength increasing mechanism by refining the grain and to provide an increase in strength along with toughness, by using titanium and vanadium together as carbide builders. The purpose of the invention is to ensure that the grain thinning elements can demonstrate their effect, thanks to the primary 1500 seconds required for the forging temperature and the post-forging cooling environment, and the heat transfer coefficient is 40-80 W/mZK. The purpose of the invention is to increase the hardness by using boron element in the steel composition. The boron element settles into the crystal structure as an interstitial atom like carbon, and due to its high solubility, it creates distortion in the crystal and increases the hardness. One aim of the invention is to improve the mechanical properties of the steel composition by taking advantage of the nitride, carbide and carbonitride forming properties of intermediate atoms such as C, N, B and elements such as Mn, Si, Ni, V and Ti. In order to fulfill the purposes described above, the invention uses micro-alloyed steel composition boron (B), max. nitrogen (N) at the rate o/00.007, by weight max. 025% silicon (Si), by weight max. 0.9% manganese (Mn), max. 0.4% chromium (Cr), by weight max. 0.1% molybdenum (M0), max. 0.2% nickel (Ni), max. by weight. 0.1% vanadium (V), 0.05-2 wt% titanium (Ti), max. 0.3% phosphorus (P), by weight max. 0.3% sulfur (S) and max. In order to realize the objectives of the invention, the steel composition produced by 0 micro alloying is obtained in billet form by the continuous casting method, and the produced billets are turned into cylindrical semi-products in the round and long group by hot rolling. It is a micro-alloyed steel composition production method that includes the process steps of precipitation formation by passing long semi-finished products through controlled hot forging and cooling stages, and its feature is; . The said forging temperature is 950-1150 °C, and the primary cooling after forging takes place under atmospheric conditions where the heat coefficient for a second is 40-80 W/mzK. The structural and characteristic features and all the advantages of the invention will be more clearly understood thanks to the detailed explanation given below, and therefore the evaluation should be made taking this detailed explanation into consideration. Detailed Description of the Invention In this detailed explanation, the high-strength, low-alloy steel composition is explained only for a better understanding of the subject and without creating any limiting effects. The invention is a micro-alloyed steel composition developed to be used in all areas where hot forging processes can be applied, and its feature is; 0.05-0.15% carbon (C) by weight, max. 0.005% boron (B), max. 000%? rate of nitrogen (N), by weight max. 0.25% silicon (Si), by weight max. 0.9% manganese (lVIn), max. 0.4% chromium (Cr), by weight max. 0.1% molybdenum (Mo), max. 02% nickel (Ni), max. by weight. 0.1% vanadium (V), 0.3% sulfur (S) by weight and max. It contains 025% copper (Cu). Formulation of the micro-alloyed steel composition subject to the invention; Content Usable Amount by Weight (%) Carbon (C) 0.05-0.15 Nitrogen (N) s 0.007 Silicon (Si) 5 0.25 Molybdenum (M0) 5 0.1 Vanadium (V) 5 0.1 Titanium ( Ti) 0.05-0.2 Phosphorus (P) 5 0.3 Copper (Cu) 5 0.25 In order to obtain the micro-alloyed steel composition subject to the invention, first the alloying elements are determined. The amount and diversity of alloying elements in the steel composition are important parameters in improving mechanical properties. In order to ensure the emergence of different strength increasing mechanisms together, the nitride, carbide and carbonitride forming properties of interstitial atoms such as C, N, B and elements such as Mn, Si, Ni, V and Ti are used. On the other hand, fine-grained and multiphase microstructure is obtained by taking advantage of the fact that TTT (isothermal transformation diagram) and CCT (continuous cooling transformation diagram) diagrams change according to the alloy element. Secondly, the hot forging methodology is created. Temperature and deformation rates in the hot forging process are rearranged according to the original alloy. Finally, apply the cooling process. The cooling regime for the target microstructure (ferrite, pearlite, bainite) is determined according to the TTT (isothermal transformation diagram) and CCT (continuous cooling transformation diagram) diagrams. In the iron-carbon phase diagram, martensite and bainite transformation has an important place in the hardening mechanism of the alloy. However, due to the process conditions in industrial steel production, cooling rates are quite high compared to equilibrium conditions. The iron-carbon phase diagram used to determine phase transformations as the cooling rate increases is not used. The most important reason for this is that the diagram in question was created under very slow cooling conditions. For this reason, diagrams called TTT, which show the change of phase transformation depending on temperature and time, are used at high cooling rates. In rapidly cooled steels, when the austenite will begin to transform, how long the transformation will take to complete, and what products will be formed as a result are determined with the help of isothermal transformation diagrams. Therefore, TTT diagrams are preferred in determining the phase transformations that will occur in the alloy under undercooling conditions as a function of temperature and time. It is necessary to change the transformation curve in order to see the effects of time and temperature separately in the transformation reaction. Curves showing this situation are called continuous cooling transformation curves (CCT). CCT diagrams can be used for all heat processes involving continuous cooling. The main purpose of CCT diagrams is to know in advance which structural elements will be obtained and which hardness will be obtained by using the cooling curve. These diagrams enable the determination of the phase or phases contained in the final microstructures to be obtained after both isothermal heat treatments in which the temperature is kept constant and the transformation in continuous cooling. Hardness increases by using boron element in the steel composition of the invention. The boron element settles into the crystal structure as an interstitial atom like carbon, and due to its high solubility, it creates distortion in the crystal and increases the hardness. By using titanium and vanadium together as carbide makers, the strength increasing mechanism by grain refinement is activated and an increase in strength along with toughness is achieved. Production method of the micro-alloyed steel composition of the invention; i Steel composition produced by micro alloying is obtained in billet form by continuous casting method using electric arc furnace, ladle furnace, vacuum furnace and tundish dip-closed ceramic tube, respectively. i Produced billets are turned into cylindrical semi-products in the round long group by hot rolling, 0 Long semi-finished products are passed through controlled hot forging and cooling stages, o With the resulting precipitate hardening mechanism, the steel alloy is forged at the desired mechanical values. The hot forging temperature used in the production method of the invention is 950-1150 °C. C-N precipitates are formed. Mechanical properties of the micro-alloyed steel composition subject to the invention; . Tensile strength 700-750 MPa, . Its hardness is 210-230 HV, its equivalent carbon value is 0.43-0.45 Ceq. In the preferred embodiment of the invention, the long product mentioned can be round, square, square with round corners, flat sheets, wide flats, etc. It covers all steel products. TR TR

Claims (7)

ISTEMLER 1. Mikro alasimli çelik kompozisyonu olup, özelligi; agirlikça %0,05-0,15 oraninda karbon1. It is a micro-alloyed steel composition and its feature is; 0.05-0.15% carbon by weight (C), agirlikça maks. %0,005 oraninda bor (B), agirlikça maks. %0,007 oraninda azot (N), agirlikça maks. %025 oraninda silisyum (Si), agirlikça maks. %0,9 oraninda mangan (lVIn), agirlikça maks. %0,4 oraninda krom (Cr), agirlikça maks. %0,1 oraninda molibden (M0), agirlikça maks. %02 nikel (Ni), agirlikça maks. %0,1 oraninda vanadyum (V), agirlikça 0,3 oraninda kükürt (S) ve agirlikça maks. %0,25 oraninda bakir (Cu) içermesidir. o mikro alasimlama ile üretilen çelik kompozisyonun sürekli döküm yöntemi ile kütük formunda elde edilmesi, - üretilen kütüklerin sicak haddeleme ile yuvarlak uzun grubunda silindirik yari mamul haline getirilmesi, 0 uzun yari mamüllerin kontrollü sicak dövme ve sogutma asamalarindan geçirilmesiyle çökelti olusmasi, islem adimlarini içeren, istem 1'de bahsedilen mikro alasimli çelik kompozisyonunun o bahsedilen dövme sicakliginin 950-1150 °C'de, dövme sonrasi birincil sogutmanin saniye süreyle isi katsayisi 40-80 W/mzK olacak sekilde atmosfer kosullarinda olmasidir.(C), max. by weight. 0.005% boron (B), max. 0.007% nitrogen (N), by weight max. 025% silicon (Si), by weight max. 0.9% manganese (lVIn), max. 0.4% chromium (Cr), by weight max. 0.1% molybdenum (M0), max. 02% nickel (Ni), max. by weight. 0.1% vanadium (V), 0.3% sulfur (S) by weight and max. It contains 0.25% copper (Cu). o Obtaining the steel composition produced by micro alloying in billet form by continuous casting method, - turning the produced billets into cylindrical semi-products in the round long group by hot rolling, 0 forming a precipitate by passing the long semi-products through controlled hot forging and cooling stages, including the process steps, The forging temperature of the micro-alloyed steel composition mentioned in 1 is 950-1150 °C, and the primary cooling after forging is at atmospheric conditions such that the heat coefficient is 40-80 W/mzK for a second. 3. Istem 2'ye uygun mikro alasimli çelik kompozisyon üretim yöntemi olup, özelligi; olusan3. It is a micro-alloyed steel composition production method in accordance with claim 2, and its feature is; formed 4. Istem 2'de bahsedilen üretim yöntemi ile elde edilen mikro alasimli çelik kompozisyonu olup, özelligi; 500-600 MPa akma mukavemetine sahip olmasidir.4. It is a micro-alloyed steel composition obtained by the production method mentioned in Claim 2, and its feature is; It has a yield strength of 500-600 MPa. 5. Istem 2'de bahsedilen üretim yöntemi ile elde edilen mikro alasimli çelik kompozisyonu olup, özelligi; 700-750 lVlPa çekme mukavemetine sahip olmasidir.5. It is a micro-alloyed steel composition obtained by the production method mentioned in Claim 2, and its feature is; It has a tensile strength of 700-750 lVlPa. 6. Istem 2'de bahsedilen üretim yöntemi ile elde edilen mikro alasimli çelik kompozisyonu olup, özelligi; 210-230 HV sertlige sahip olmasidir.6. It is a micro-alloyed steel composition obtained by the production method mentioned in Claim 2, and its feature is; It has a hardness of 210-230 HV. 7. Istem 2'de bahsedilen üretim yöntemi ile elde edilen mikro alasimli çelik kompozisyonu olup, özelligi; 0,43-0,45 Ceq esdeger karbon degerine sahip olmasidir.7. It is a micro-alloyed steel composition obtained by the production method mentioned in Claim 2, and its feature is; It has an equivalent carbon value of 0.43-0.45 Ceq.
TR2019/21217A 2019-12-24 2019-12-24 High strength, low alloy steel composition TR201921217A2 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
TR2019/21217A TR201921217A2 (en) 2019-12-24 2019-12-24 High strength, low alloy steel composition
PCT/TR2020/051351 WO2021133343A1 (en) 2019-12-24 2020-12-22 High strength, low alloy steel composition

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
TR2019/21217A TR201921217A2 (en) 2019-12-24 2019-12-24 High strength, low alloy steel composition

Publications (1)

Publication Number Publication Date
TR201921217A2 true TR201921217A2 (en) 2021-07-26

Family

ID=74096042

Family Applications (1)

Application Number Title Priority Date Filing Date
TR2019/21217A TR201921217A2 (en) 2019-12-24 2019-12-24 High strength, low alloy steel composition

Country Status (2)

Country Link
TR (1) TR201921217A2 (en)
WO (1) WO2021133343A1 (en)

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2335200A (en) 1998-03-10 1999-09-15 British Steel Plc Steel composition
JP4073860B2 (en) * 2003-11-11 2008-04-09 山陽特殊製鋼株式会社 Manufacturing method of carburized steel with excellent coarsening resistance after high-temperature carburizing
DE102006041146A1 (en) 2006-09-01 2008-03-06 Georgsmarienhütte Gmbh Steel and processing methods for the manufacture of high-strength fracture-breakable machine components
JP6119691B2 (en) * 2014-07-31 2017-04-26 Ｊｆｅスチール株式会社 Forged steel pipe excellent in widening workability, its manufacturing method and manufacturing equipment
JP6213703B1 (en) * 2016-03-22 2017-10-18 新日鐵住金株式会社 ERW steel pipe for line pipe
WO2018008194A1 (en) * 2016-07-06 2018-01-11 新日鐵住金株式会社 Electroseamed steel pipe for line pipe
CN109642284B (en) * 2016-10-03 2021-04-20 新日铁住金株式会社 Electric Welded Steel Pipe for Torsion Beam

Also Published As

Publication number Publication date
WO2021133343A1 (en) 2021-07-01

Similar Documents

Publication Publication Date Title
Knyazeva et al. Duplex steels: part I: genesis, formation, structure
JP5833751B2 (en) Ultra-high strength wear-resistant steel sheet and method for producing the same
TWI742812B (en) Wear-resistant steel plate and manufacturing method thereof
TR201921223A2 (en) Composition of micro-alloyed steel with improved mechanical properties
RU2763027C1 (en) Forged part made of bainite steel and its manufacturing method
JP2014520954A5 (en)
CA3042120A1 (en) Medium-manganese steel product for low-temperature use and method for the production thereof
US20140322066A1 (en) Rolled steel bar for hot forging
JP6819198B2 (en) Rolled bar for cold forged tempered products
EP3209806A1 (en) An ultra-high strength thermo-mechanically processed steel
CN110139942A (en) High hardness wear-resisting steel and its manufacturing method
JP6217671B2 (en) Thick steel plate with excellent wear resistance in high temperature environments
US20220042152A1 (en) Abrasion resistant steel having excellent hardness and impact toughness and manufacturing method therefor
US20120315181A1 (en) Stainless mold steel with lower delta ferrite content
RU2251587C2 (en) Structural steel
JP2009228051A (en) Method for producing non-heattreated steel material
TR201921217A2 (en) High strength, low alloy steel composition
KR20180001704A (en) Steel having film type retained austenite
RU2456368C1 (en) High-strength dynamic impact resistant steel and method for production of this steel sheets
Fonstein Martensitic sheet steels
EP1984527B1 (en) Method of production of high-strength low-alloyed steel pipes
RU2652281C1 (en) Method of production of hot-rolled sheets from high-strength steel
EP4211283A1 (en) Forged part of steel and a method of manufacturing thereof
TR2021012361A2 (en) New generation micro alloy steel
WO2023014331A2 (en) Next-generation micro-alloyed steel