ÖSTENİTLEME SICAKLIĞININ EN-GJS-600-3 KÜRESEL GRAFİTLİ DÖKME DEMİRİN ÖSTEMPERLENME DAVRANIŞINA ETKİLERİNİN ARAŞTIRILMASI

Year 2020, Volume: 8 Issue: 3, 706 - 722, 03.09.2020

Erkan Konca , Kazım Tur

https://doi.org/10.36306/konjes.705209

Cited By: 1

Abstract

Bu çalışmada östenitleme sıcaklığının EN-GJS-600-3 (GGG-60) küresel grafitli dökme demirin
östemperlenme davranışına etkisi araştırılmıştır. Y bloklarına dökülen % 0,5 Cu alaşımlı EN-GJS-600-3
küresel grafitli dökme demirden çıkarılan numuneler kullanılarak iki farklı östenitleme sıcaklığı (850 ve
950°C) ve iki farklı östemperleme sıcaklığının (290 ve 320°C) dört ayrı kombinasyonunda östemperleme
deneyleri yapılmıştır. Östemperleme deneyleri sonrası numunelerin sertlik ölçümleri, çekme testleri ve iç
yapı incelemeleri gerçekleştirilmiştir. Her iki östemperleme sıcaklığında da 950°C’de östenitlenmiş
numunelerde 850°C’de östenitlenmiş numunelere göre daha yüksek sertlik, akma ve çekme dayanımı
değerlerine ulaşılmıştır. Bu sonuçlar, 950°C’de yapılan östenitlemenin 850°C’ye göre östenit matris içinde
hem daha çok karbonun çözünmesini hem de östenitin daha iri taneli olmasını sağlayarak
östemperlenmeye daha elverişli östenit yapısı oluşturabilmesiyle ilişkilendirilmiştir.

Keywords

EN-GJS-600-3, östemperleme, östemperlenmiş sünek dökme demir, ösnitleme, östenitleme sıcaklığı, östenit karbon içeriği, östenit tane boyutu, segregasyon

Thanks

EN-GJS-600-3 alaşımından Y blokların döküldüğü Ekstrametal Döküm İzaba ve Mak. San. Tic. Ltd. Şti’ne, metalografik numune hazırlıkları için Özdemir Dinç’e, sertlik ölçümleri için Yaşar Kazanç’a ve çekme testleri için Erkin Koç’a teşekkür ederiz.

Investigation of the Effects of Austenitizing Temperature on the Austempering Behavior of EN-GJS- 600-3 Spheroidal Graphite Cast Iron

Abstract

The effect of austenitizing temperature on the austempering behavior of EN-GJS-600-3
(GGG-60) spheroidal graphite cast iron was investigated. 0.5% Cu alloyed EN-GJS-600-3 spheroidal
graphite cast iron samples obtained from Y-blocks were subjected to four different austempering
experiments as a combination of two different austenitizing (850 and 950°C) and two different
austempering temperatures (290 and 320°C). Hardness measurements, tensile tests and microstructural
examinations were performed after the austempering experiments. The samples austenitized at 950°C
produced higher hardness, yield and tensile strength values as compared to the samples austenitized at
850°C. This observation was linked to the fact that as compared to 850°C austenitizing at 950°C provided
both more carbon to dissolve in the austenite matrix and larger austenite grain size resulting in better
austemperability.

Keywords

EN-GJS-600-3, austempering, austempered ductile iron, austenitizing, austenitizing temperature, austenite carbon content, austenite grain size, segregation

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