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

Yıl 2021, , 208 - 214, 29.05.2021

Candan Sen Elkoca

https://doi.org/10.29130/dubited.837324

Öz

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

Öz

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

Anahtar Kelimeler

Bor alaşımlı çelik, suverme, ısıl işlem

Kaynakça

• [1] I. Mejía, A. Bedolla-Jacuinde, C. Maldonado, J.M. Cabrera, “Hot ductility behaviour of a low carbon advanced high strength steel (AHSS) microalloyed with boron”, Materials Science and Engineering A, Vol. 528, No. 13-14, pp. 4468-4474, 2011.
• [2] A. Terzic, M. Calcagnotto, S. Guk, T. Schulz, R. Kawalla, “Influence of Boron on transformation behavior during continuous cooling of low alloyed steels”, Materials Science & Engineering A, Vol. 584, pp. 32-40, 2013.
• [3] T. I. Titova, N. A. Shulgan, I. Yu Malykhina, “Effect of boron microalloying on the structure and hardenability of building steel”, Metal Science and Heat Treatment, Vol. 49, No. 1-2, pp. 39-44, 2007.
• [4] K. S. Chandravathia, K. Laha, N. Shinyab, M. D. Mathewa, “Effects of Boron and Cerium on Creep Rupture Properties of Modified 9Cr-1Mo Steel and its Weld Joint”, Procedia Engineering, Vol. 55, pp. 433-437, 2013.
• [5] Z. P. Luo, C. Y. Sun, “Effect of the interfacial bonding status on the tensile fracture characteristics of a boron–fiber-reinforced aluminum composite”, Materials Characterization, Vol. 50, No.1, pp. 51-58, 1999.
• [6] W. Chen, C. J. Boehlert, E. A. Payzant, J. Y. Howe, “The effect of processing on the 455 oC tensile and fatigue behavior of boron-modified Ti–6Al–4V”, International Journal of Fatigue, Vol. 32, No. 3, pp. 627-638, 2010.
• [7] W. Chen, C. J. Boehlert, “The 455 oC tensile and fatigue behavior of boron-modified Ti–6Al–2Sn–4Zr–2Mo–0.1Si (wt.%)”, International Journal of Fatigue, Vol. 32, No. 5, pp. 799-807, 2010.
• [8] H. Güler, R. Ertan, R. Özcan, “Characteristics of 30MnB5 boron steel at elevated temperatures”, Materials Science and Engineering: A, Vol. 578, pp. 417-421, 2013.
• [9] M.‐Y. Tu, C.‐A. Hsu, W.‐H. Wang, and Y.‐F. Hsu, “Comparison of microstructure and mechanical behavior of lower bainite and tempered martensite in JIS SK5 steel”, Materials Chem. and Physics, 107(2‐3): 418‐425, 2008.
• [10] A. G. Foley, P. J. Lawton, A. W. Barker, V. A. Mclees, “The Use of Alumina Ceramic to Reduce Wear of Soil-engaging Components”, J. Agric. Engng. Res., 30, 37-46, 1984.
• [11] J. S. Kim, K.-T. Park, D. Lee, C. S. Lee, “Effect of Intergranular Ferrite on Hydrogen Delayed Fracture Resistance of High Strength Boron-added Steel”, ISIJ International, 47(6):913-919, 2007.
• [12] C. A. Suski ve C. A. S. de Oliveira, “Effect of Austenitization Temperature on the Precipitation of Carbides in Quenched Low Carbon Boron Steel”, Metallography Microstructure and Analysis, 2(2):79–87, 2013.