The Effect of Austenitizing Temperature on the Hardness and Toughness Properties of Boron Alloyed 30MnB5 Steel

Abstract

In this study, the effect of austenitizing temperature on the hardness and toughness properties of 30MnB5 boron alloyed steel after quenching and tempering processes was investigated. In the study, the prepared Charpy notched test specimens, which were subjected to austenitization process at various temperatures, were hardened by quenching and then tempered at 200 oC. Hardness measurements and impact tests were carried out on the tempered samples. After the impact test, the fractured surfaces of the broken samples were examined through scanning electron microscope and the microstructures of the samples prepared by the metallographic method were examined under optical microscope. Based on the data obtained, the austenitizing condition that gives optimum hardness and toughness was determined.
Keywords: Boron-alloyed steel, 30MnB5, Heat treatment, Quenching, Tempering

Ostenitleme Sıcaklığının Bor Alaşımlı 30MnB5 Çeliğinin Sertlik ve Tokluk Özelliklerine Etkisi

Abstract

Bu çalışmada, bor alaşımlı 30MnB5 çeliğinin farklı ostenitleme koşulları sonrasındaki sertlik ve tokluk özellikleri incelenmiştir. Çalışmada farklı sıcaklıklarda ostenitleme işlemine tabi tutulan Charpy çentikli test numuneleri su verme işlemi ile sertleştirilmiş ve ardından 200 oC’de menevişlenmiştir. Menevişlenen numuneler üzerinde sertlik ölçümleri yapılmış ve darbe testleri gerçekleştirilmiştir. Darbe testi sonrasında kırılan numunelerin kırık yüzeyleri taramalı elektron mikroskobunda incelenmiş ve metalografik yöntemle hazırlanan numunelerin mikroyapıları optik mikroskopta incelenmiştir. Elde edilen verilere dayanarak optimum sertlik ve tokluk özelliğini veren ostenitleme koşulu belirlenmiştir.
Anahtar Kelimeler: Bor alaşımlı çelik, 30MnB5, Isıl işlem, Su verme, Menevişleme

Keywords

• Bor alaşımlı çelik
• suverme
• ısıl işlem

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