54SiCr6 ve 60SiMn5 Yay Çeliklerinin Isıl İşlemi ve Mikroyapısal Analizi

Öz

Dünya üzerinde en fazla kullanılan alaşım olan çelik, malzeme biliminin en net işlevi olan malzemelerdeki yapı-özellik-performans ilişkisinin incelenmesinde en somut örnektir. Çelikler katı çözeltide başka bir element atomlarıyla buluşmasıyla çok farklı özellikler sergilemektedir bu özellik değişimlerine bağlı olarak ise kullanıldığı alanda malzemenin performansını belirlemektedir. Silisyum elementi çeliklere belirli oranlarda eklendiğinde endüstride çeliğin yay çeliği olarak kullanılmasında gerekli mekanik özellikleri sağlamakta önem taşır ve genelde bu çelikler silisyum yay çelikleri olarak sınıflandırılır. Çeliklerin kimyasal karakterin dışında özellik ve performanslarını belirlemek, düzenlemek ve geliştirmek için ısıl işlemler uygulanır. Bu ısıl işlemler farklı amaçlarla farklı yöntemlerle yapılmaktadır. Bu çalışmada, silisyum içeren yay çeliklerinin üretildiğinde sahip olduğu sertliğin daha sonra ani soğutmada, soğutma ortamı olarak su kullanıldığında veya yağ kullanıldığında nasıl tepki verdiği sertleştirme işlemi akabinde temperleme ile nihai sertlik ve iç yapıları incelenmiştir. Sonuçlar göstermiştir ki, su verme işleminden sonra, 54SiCr6 çeliği, tam martenzitik 60MnSi5 çeliğine göre, martenzit+beynit yapısında mikroyapı üretilmiştir.

Anahtar Kelimeler

• 54SiCr6 Çeliği
• 60SiMn5 Çeliği
• Isıl işlem
• Mikroyapı

Heat Treatment and Microstructural Analysis of 54SiCr6 and 60SiMn5 Spring Steels

Abstract

Steels, the most widely used alloy in the world, are the most concrete example in the study of the structure-property-performance relationship in materials, which is the clearest function of the science of materials. Steels exhibit very different properties when other types of atom are present in the solid solution. Due to these changes in properties, the performance of the material in the area of use is determined. When silicon is added to steels in certain proportions, it is important to provide the necessary mechanical properties in steel industry as spring steel, and these steels are generally classified as silicon spring steels. Heat treatments are applied to determine, regulate and improve the properties and performances of steels other than their chemical properties. These heat treatments are carried out with different methods for different purposes. In this study, the hardness of silicon containing spring steels when it is produced, then how hard it reacts in sudden cooling, when water or oil is used as cooling medium, the final hardness and microstructures are examined by tempering followed by hardening. Results showed that 54SiCr6 produced martensite+bainite structure as opposed to fully martensitic 60SiMn5 specimen after quenching process.

Keywords

• 54SiCr6 Steels
• 60SiMn5 Steels
• Heat treatment
• Microstructure

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