The Effect of Titanium on Microstructure and Hardness in High Alloy White Cast Iron

Abstract

High alloy white cast iron materials are widely used in cement, concrete and mining industries due to high wear resistance. In this study, the effect of titanium on microstructure and hardness properties in white cast iron materials was investigated. For this purpose, cast materials were alloyed by melting at in induction furnace to include titanium with the rates of % 0, % 0.5, % 0.1, % 1.5, % 2 and were formed by casting into the metal mould. Specimens with different contents of titanium were applied hardening on air after heat treatment at 850 ˚C for 5 hours and tempered at 250 ˚C for 4 hours. Microstructure of cast and heat treated specimens were investigated by using light microscope and scanning electron microscope (SEM). In the microstructure investigations, it was observed that titanium has a significant effect on carbide morphology. It was seen that the hardness of the material with heat treatment increases significantly according to the casting condition. Also it was observed that highest hardness values were obtained with the specimens that include %1 Ti.

Keywords

• Cast Iron
• Titanium
• Heat Treatment
• Microstructure
• Hardness

Yüksek Alaşımlı Beyaz Dökme Demirde Titanyum Katkısının Mikroyapı ve Sertlik Üzerine Etkisi

Abstract

Yüksek alaşımlı beyaz dökme demir malzemeler yüksek aşınma dayanımından dolayı çimento, beton ve madencilik sektörlerinde geniş bir kullanım alanına sahiptir. Bu çalışmada, yüksek alaşımlı beyaz dökme demir malzemelerde titanyum katkısının mikroyapı ve sertlik özelliklerine etkisi incelenmiştir. Bu amaçla, döküm malzemeler % 0.5,  % 1 % 1.5 ve % 2 oranlarında titanyum içerecek şekilde indüksiyon ocağında ergitilerek alaşımlandırılmış ve metal kalıba dökülerek şekillendirilmiştir. Farklı oranlarda titanyum içeren numunelere   850 ˚C’ de 5 saat süreyle tavlama yapılarak havada sertleştirilmiş ve devamında 250 ˚C’ de 4 saat süreyle temperleme işlemi uygulanmıştır. Döküm konumundaki ve ısıl işlem uygulanmış numunelerde ışık mikroskobu ve elektron mikroskobu (SEM) ile mikroyapı incelemeleri yapılmıştır.  Artan titanyum oranı ve ısıl işlem koşullarına bağlı olarak malzemelerin mikroyapı ve sertlik özelliklerinde meydana gelen değişimler karşılaştırmalı olarak incelenmiştir.

Keywords

• Dökme Demir
• Titanyum
• Isıl İşlem
• Mikroyapı
• Sertlik

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