Tuna AYDOĞMUŞ, Bünyamin ÇİÇEK, Polat TOPUZ, Özlem AYDIN

Borlanmış AISI M2 Yüksek Hız Çeliğinde Tek Fazlı (Fe2B) Borür Tabakası Oluşumu

Bu çalışmada AISI M2 Yüksek Hız Çeliği kutu-borlama yöntemi ile borlanmıştır. Numuneler atmosferik kontrollü fırında 900 ila 1100 C'de 2 ila 6 saat süreyle borlanmıştır. Borlama ısıl işlemi için AISI 316 paslanmaz çelik pota ve borlama maddesi olarak ticari ismi EKABOR 2 olan toz karışımı kullanılmıştır. Borlama işleminden sonra numuneler metalografik olarak hazırlanmıştır. Mikroyapı ve kimyasal analiz incelemeleri için taramalı elektron mikroskobu (SEM) ve entegre EDX (Energy Dispersive X-Ray Analysis) ünitesi kullanılmıştır. SEM (BEI) ve EDX incelemeleri sonucunda, diğer birçok çelik türünden farklı olarak malzeme yüzeyinde sadece tek fazlı (Fe2B) borür tabakası oluşmuştur. Mikroskobik incelemelerden sonra numunenin sertliğini ölçmek için Vickers indenteri yardımıyla 100 gr. ağırlık kullanılmıştır. Deneysel çalışmalar sonucunda, AISI M2 yüksek hız çeliğinin borlanabileceği, borlama sıcaklığı ve süresinin artmasıyla borür tabakasının kalınlığının arttığı tespit edilmiştir. Ayrıca borür tabakasının matris metalden yaklaşık 5 kat daha sert olduğu tespit edilmiştir.

Anahtar Kelimeler:

AISI M2, kutu borlama, Ekabor 2, borür tabakası, Fe2B fazı, sertlik

Single Boride Layer (Fe2B) Formation of Borided AISI M2 High-Speed Steel

In this study, AISI M2 High-Speed Steel was borided by a pack-boriding method. Samples were borided in the atmospheric controlled furnace at 900 to 1100 C for 2 to 6h. For the boriding heat treatment, AISI 316 stainless steel crucible and a powder mixture with the trade name EKABOR 2 as the boriding agent were used. After the boriding treatment, samples were metallographically prepared. A scanning electron microscope (SEM) and integrated EDX (Energy Dispersive X-Ray Analysis) unit were used for the microstructure and chemical analysis examinations. As a result of SEM (BE) and EDX examinations, only a single-phase (Fe2B) boride layer is formed on the material surface, unlike many other types of steel. After microscopic examinations, the sample’s hardnesses were measured with the help of the Vickers indenter by 100g. As a result of the experimental studies, it was determined that AISI M2 high-speed steel can be borided, and the thickness of the boride layer increases with the increase in boriding temperature and time. In addition, it has been determined that the boride layer is approximately 5 times harder than the matrix metal.

Keywords:

AISI M2, pack boriding, Ekabor 2, boride layer, Fe2B phase, hardness,

PDF

___

1. R. Adair, Boron (Understanding the Elements of the Periodic Table), Rosen Publishing Group, 29 East 21st St. New York, NY 10010 (2007) 19.
2. Yinghuai Zhu, Fundamentals and Applications of Boron Chemistry / Developments in Inorganic Chemistry, Vol.2, Elsevier, pp. 1-430, 2022.
3. Tsipas D.N.,Tsipas S.A.,”Boronizing of Iron-Based Alloys”, Encyclopedia of Iron, Steel and Their Alloys,Page: 376-400, 2015.
4. P. Topuz: Development of Boronizing Parameters and Boronizing of Different Steels in Fluidized Bed Furnace, Doctoral Thesis, Marmara University, Turkey (2010).
5. A. K. Sinha: Boriding (Boronizing). ASM Handbook, Vol. 4: Heat Treating, ASM International, Materials Park, OH, USA (1999), pp. 437-447.
6. M. Keddam, S. M. Chentouf: A diffusion model for describing the bilayer growth (FeB/Fe2B) during the iron powder-packboriding, Applied Surface Science 252 (2005), No. 2, pp. 393-399.
7. Velázquez-Altamirano, J.C.; Torres-Avila, I.P.; Teran-Méndez, G.; Capula-Colindres, S.I.; Cabrera-Sierra, R.; Carrera-Espinoza, R.; Hernández-Sánchez, E. A Stochastic Model and Investigation into the Probability Distribution of the Thickness of Boride Layers Formed on Low-Carbon Steel. Coatings 2019, 9, 756.
8. Jain, V.; Sundararajan, G.: “Influence of the Pack Thickness of the Boronizing Mixture on the Boriding of the Steel”, Surface & Coatings Technology, (2002) s.21-26.
9. Dossett, Jon L.; Totten, George E., eds. (2013). "Boriding (Boronizing) of Metals". Steel Heat Treating Fundamentals and Processes. ASM International. pp. 709–724.
10. M. Keddam, M. Kulka, Boriding kinetics of AISI D2 steel by using two different approaches, Metal Science and Heat treatment, 61 (2020) 11-12, pp.756-763.
11. Campos-Silva, I., Ortiz-Domínguez, M., Bravo-Bárcenas, O., Doñu-Ruiz, M. A., Bravo-Bárcenas, D., Tapia-Quintero, C., & Jiménez-Reyes, M. Y.: Formation and kinetics of FeB/Fe2B layers and diffusion zone at the surface of AISI 316 borided steels. Surface and Coatings Technology, 205 (2010) 2, 403–412.
12. C. Zouzou and M. Keddam, Boriding kinetics of FeB and Fe2B layers on AISI M2 steel by the integral diffusion model, Ann. Chim-Sci. Mat., 43 (2019) 3, pp. 159 - 164.
13. Yu, L., Khor, K., & Sundararajan, G.: Boriding of mild steel using the spark plasma sintering (SPS) technique. Surface and Coatings Technology, 157 (2002) 2-3, pp.226–230.
14. Topuz P; Gündoğdu İ. E; Yılmaz E. (2014). Kinetic Investigations of Boronized Cold Work Tool Steels. Materials Testing, 56(2), 104-110.
15. Youssouph Mandiang, Lioudmila Fadeievna Pavlovskaya, Irina Anatolievna Basalai, Natalia Gueorguievna Koukhareva / International Journal of Engineering Research and Applications (IJERA) Vol. 3, Issue 4, 2013, pp.600-604.
16. I. Campos, G. Ramírez, U. Figueroa, J. Martínez, O. Morales, Evaluation of boron mobility on the phases FeB, Fe2B and diffusion zone in AISI 1045 and M2 steels, Applied Surface Science, Volume 253, Issue 7, 2007, Pages 3469-3475.
17. J.A. Davis, P.J. Wilbur, D.L. Williamson, R. Wei, J.J. Vajo, Ion implantation boriding of iron and AISI M2 steel using a high-current density, low energy, broad-beam ion source, Surface and Coatings Technology, Volumes 103–104, 1998, Pages 52-57.
18. MG Krukovich, BA Prusakov, IG Sizov. Plasticity of Boronized Layers, The Equilibrium Diagram of ‘Boron-Iron’ Binary System, Springer International Publishing, 2016.
19. Shaoming, Kang & Xu, Z.F. & Choi, Yong & Fujita, Kenji & Matsugi, Kazuhiro & Yu, Jinku. (2016). Spark Sintering Behavior of Ubiquitously Fe-B and Fe Powders and Characterization of Their Hard Composites. Materials Transactions. 57. 600-607. 10.2320/matertrans.MC201506. 20. Jibo Jiang, Yi Wang, Qingdong Zhong, Qiongyu Zhou, Lei Zhang, Preparation of Fe2B boride coating on low-carbon steel surfaces and its evaluation of hardness and corrosion resistance, Surface and Coatings Technology, Volume 206, Issues 2–3, 2011, Pages 473-478.