THE USE OF SiC MATERIALS AS INOCULANTS IN GRAY CAST IRON AND THEIR EFFECTS ON MECHANICAL PROPERTIES

Öz

Gray cast irons hold a significant place in the industry due to their excellent casting and engineering properties as well as their superior performance in various applications. Although the graphite flakes in the matrix structure result in lower hardness, strength, and impact resistance compared to steel and spheroidal graphite iron, gray cast iron is the most widely used material among iron-based groups in both the world and in Turkey due to its superior thermal conductivity and vibration damping capability. Various studies have been carried out to improve the weak properties caused by flake graphite through inoculation and other composition-based liquid metal treatments.The aim of this study is to investigate the effect of different inoculation processes on the microstructural and mechanical properties of gray cast iron materials. In the experimental studies, flow inoculation was applied during the pouring of the molten metal into the mold, and three different inoculants green SiC, metallurgical SiC, and a barium-containing additive were used. These samples, both uninoculated and inoculated with different materials, were evaluated through thermal analysis, microstructural examination, and mechanical tests. The results obtained from thermal analysis revealed that the eutectic temperature, recalescence, and graphite formation tendency changed depending on the inoculation process parameters. While D- and E-type graphite structures were predominantly observed in uninoculated samples, A-type graphite was formed in the inoculated samples, resulting in a more homogeneous structure. In the inoculated materials, due to the increased ferrite content, a decrease in hardness values and an increase in tensile and yield strength were observed. The findings of the study clearly demonstrate that inoculation is a significant factor that leads to improvements in not only graphite morphology but also in mechanical properties.

Anahtar Kelimeler

• Gray cast iron
• thermal analysis
• casting simulation
• microstructure
• hardness

Destekleyen Kurum

Erkunt Sanayi A.Ş.

Proje Numarası

E24-019

Etik Beyan

This study has been prepared in accordance with the principles of scientific research and publication ethics. All sources used in the research process have been accurately and completely cited, and information taken from other studies has been used with appropriate references. No unethical practices such as plagiarism, data fabrication, falsification, duplicate publication or unjust authorship have been employed at any stage of the study. As the author, I declare that the study is original and has been completed in accordance with ethical rules.

Teşekkür

This study was supported by Erkunt Sanayi A.Ş. We would like to express our gratitude to the R&D Centre Directorate for their contributions.

SiC MALZEMELERİN GRİ DÖKME DEMİRDE AŞILAYICI OLARAK KULLANIMI VE MEKANİK ÖZELLİKLERE ETKİSİ

Öz

Gri dökme demirler, üstün döküm ve mühendislik özellikleri ve kullanım alanlarında sergilediği üstün performans endüstride önemli bir yer tutmaktadır. Matris yapıda mevcut grafit lamelleri, çelik ve sfero malzemeye göre düşük sertlik, mukavemet, darbe direnci sergilemesine rağmen ısı iletkenliğinin ve titreşim söndürme kabiliyetinin yüksek olması gibi üstünlükleri sayesinde demir esaslı gurupta Dünyada ve ülkemizde en fazla kullanım alanı bulmuş malzemedir. Lamel grafitlerin neden olduğu zayıf özellikleri iyileştirmek için, aşılamaya ve diğer bileşime dayalı sıvı işlemelere yönelik çeşitli çalışmalar yürütülmüştür. Bu çalışmanın amacı, farklı aşılama işlemlerinin, gri dökme demir malzemelerin mikroyapısal ve mekanik özelliklere etkisini araştırmaktır. Deneysel çalışmalarda, sıvı metalin kalıba dökümü sırasında akışa aşılama yöntemi uygulanmış olup, çalışma kapsamında yeşil SiC, metalurjik SiC ve baryum içeren üç farklı aşılayıcı kullanılmıştır. Aşılanmamış ve farklı malzemeler ile aşılanmış olan bu numuneler; termal analiz, mikroyapı incelemesi ve mekanik testler gerçekleştirilerek değerlendirilmiştir. Uygulanan termal analiz verilerinden elde edilen sonuçlar, ötektik sıcaklık, geri ısınma miktarı ve grafitleşme eğiliminin, aşılama işlem parametreleri ile değişim gösterdiğini ortaya koymuştur. Aşılama işlemi uygulanmamış numunelerde D ve E tipi grafit yapıları yoğun olarak gözlenirken, aşılanmış olan numunelerde A tipi grafit oluşumunun gerçekleştiği ve daha homojen bir yapının elde edildiği belirlenmiştir. Aşılama işlemi uygulanan malzemelerde, artan ferrit oranına bağlı olarak, sertlik değerlerinde azalma, çekme ve akma mukavemetinde artış sağlanmıştır. Çalışma sonuçları, aşılama işleminin, grafit morfolojisinin yanında mekanik özelliklerde önemli gelişme sağlayan bir etken olduğunu açıkça ortaya koymaktadır.

Anahtar Kelimeler

• Gri dökme demir
• termal analiz
• döküm simülasyonu
• mikroyapı
• sertlik.

Destekleyen Kurum

Erkunt Sanayi A.Ş.

Proje Numarası

E24-019

Etik Beyan

Bu çalışma, bilimsel araştırma ve yayın etiği ilkeleri gözetilerek hazırlanmıştır. Araştırma sürecinde kullanılan tüm kaynaklar doğru ve eksiksiz biçimde belirtilmiş, başka çalışmalardan alınan bilgiler ise uygun şekilde atıf yapılarak kullanılmıştır. Çalışmanın hiçbir aşamasında intihal, veri tahrifi, sahtecilik, tekrar yayın veya haksız yazarlık gibi etik dışı uygulamalara yer verilmemiştir. Yazar olarak, çalışmanın özgünlüğünü ve etik kurallara bağlı kalınarak tamamlandığını beyan ederim.

Teşekkür

Bu çalışma Erkunt Sanayi A.Ş. tarafından desteklenmiştir. Katkılarından dolayı Ar-Ge Merkezi Müdürlüğü’ne teşekkürlerimizi sunarız.

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