NiHARD-4 BEYAZ DÖKME DEMİRİN KATILAŞMA DAVRANIŞININ SİMÜLASYONU VE METALURJİK KARAKTERİZASYONU

Year 2024, Volume: 29 Issue: 2, 431 - 442, 30.08.2024

Gülşah Aktaş Çelik

https://doi.org/10.17482/uumfd.1432823

Abstract

NiHard-4 beyaz dökme demir tarım ve madencilik endüstrilerinde yüke, katı partikül erozyonuna ve aşınmaya maruz kalan iş parçalarında çoğunlukla kullanılan bir malzemedir. Katılaşma yapısının metalurjik olarak tanımlanması, katılaşmada mikrosegregasyonun izlenmesi ve tüm faz dönüşümlerine ait kritik sıcaklıkların tanımlanması dökme demirin tokluğunun ve aşınma direncinin optimizasyonunda önemli bir rolü olan ısıl işlem koşullarının belirlenmesine katkı sağlar. Bu çalışmada, NiHard-4 beyaz dökme demir kompozisyonu üzerine Thermo-Calc hesaplamaları kullanılarak termodinamik bir modelleme yapılmıştır. Böylece dökme demirde katılaşma sıralaması, faz dönüşümleri ve elementel mikrosegregasyonlar hesaplanmıştır. Hesaplamalar; (i) dökme demirin katılaşma yapısında östenit ve Cr-ca zengin M7C3 ötektik karbürlerin var olduğunu, (ii) katılaşmanın sıvıdan östenit fazının kristallenmesi ile başladığını ve ötektik katılaşma sonrası tamamlandığını ve (iii) C, Cr, Mn ve Fe elementlerinin pozitif segregasyona karşılık Si ve Ni elementlerinin negatif segregasyona eğilimi olduğunu göstermiştir. Y blok olarak kum kalıba dökümü gerçekleştirilen dökme demir üzerine yapılan mikroyapısal ve termal karakterizasyon çalışmaları alaşımın katılaşma davranışını, kritik faz dönüşüm sıcaklıklarını ve elementlerin segregasyon eğilimini modele göre doğrulamıştır.

Keywords

NiHard-4 beyaz dökme demir, CALPHAD, Thermo-Calc, katılaşma, karakterizasyon.

Simulation of Solidification Behavior of Nihard-4 White Cast Iron and Its Metallurgical Caracterization

Abstract

NiHard-4 white cast iron is a material mostly used in workpieces subject to load, solid particle erosion and wear in the agricultural and mining industries. Metallurgical definition of the solidification structure, monitoring microsegregation in solidification and identification of critical temperatures for all phase transformations contribute to the determination of heat treatment conditions, which have an important role in optimizing toughness and wear resistance of cast iron. In this study, a thermodynamic modeling is carried out using the CALPHAD methodology on the composition of NiHard-4 white cast iron. Thus, solidification sequence, phase transformations and elemental microsegregations in cast iron are calculated. Calculations reveal that (i) austenite and Cr-rich M7C3 eutectic carbides are present in solidification structure, (ii) solidification begins with the crystallization of the austenite phase from the liquid and is completed after eutectic solidification, and (iii) C, Cr, Mn and Fe elements tend to have positive segregation, whereas Si and Ni elements tend to have negative segregation. Microstructural and thermal characterization studies on cast iron produced as Y block in a sand mold confirm the solidification behavior of the alloy, critical phase transformation temperatures and segregation tendency of the elements according to the model.

Keywords

NiHard-4 white cast iron, CALPHAD, Thermo-Calc, solidification, characterization.

References

• Akyıldız, Ö., Candemir, D., Yıldırım, H. (2018) Simulation of phase equilibria in high chomium white cast irons, Uludağ University Journal of The Faculty of Engineering, 23, 179 – 190, https://doi.org/10.17482/uumfd.333701
• Al-Rubaie, K. S., Pohl, M.. (2014) Heat treatment and two-body abrasion of Ni-hard 4, Wear, 312, 21 – 28, https://doi.org/10.1016/j.wear.2014.01.013
• Bedolla-Jacuinde, A., Guerra, F. V., Mejía, I., Zuno-Silva, J., Rainforth, M., (2015), Abrasive wear of V-Nb-Ti alloyed high-chromium white irons, Wear, 332 – 333, 1006 – 1011, https://doi.org/10.1016/j.wear.2015.01.049
• Berns, H., Theisen, W. (2008) Ferrous materials, steel and cast iron. Springer-Verlag, Berlin Heidelberg.
• Bhadeshia, H. K. D. H. & Honeycombe, R. W. K. (2017) Steels: microstructure andproperties. (4th ed.) Butterworth-Heinemann, Oxford, UK.
• Davis, J. R. (1996) ASM specialty handbook cast iron; classification and basic metallurgy of cast irons. ASM International.
• Erkoçak, Y., Kayır, Y. (2023) Analyzing the impacts of cutting parameters on cutting forces in the Taguchi Method for boring high-alloy white cast irons with CBN inserts, Arabian Journal for Science and Engineering, 48, 12569 – 12585, https://doi.org/10.1007/s13369-023- 08008-z
• Guerra Lopez, F.V., Beltz-Perez, T. (2023) Bedolla-Jacuinde, A. et al. Effect of Mn and Al additions on the microstructure and hardness of a high Cr white cast iron for severe wear applications. MRS Advances 8, 1177–1181. https://doi.org/10.1557/s43580-023-00714-y
• Gushchin, N. S., Gudenko, A. S., Korneev, A. A. (2020) Effect of silicon and vanadium on the composition of carbide phase in mottled medium-alloy chromium-nikel cast iron, Metal Sciene and Heat Treatment, 62, 3 – 4, https://doi.org/10.1007/s11041-020-00542-z
• Gushchin, N. S., Takhirov, A. A., Nuraliev, F. A., Adreev, V. V. (2018) Special features of formation of cast structure of chromium-nikel iron, Metal Science and Heat Treatment, 60, 7 – 8, https://doi.org/10.1007/s11041-018-0294-2
• Haidemenopoulos, G. N. (2018) Physical metallurgy, principles and design. Taylor & Francis_CRC Press.
• Hashimoto, M., Kubo, O., Matsubara, Y. (2004) Analysis of carbides in multi-component white cast iron for hot rolling mill rolls, ISIJ International, 44, 372 – 380, https://doi.org/10.2355/isijinternational.44.372
• Heinoa, V., Kalliob, M., Valtonena, K., Kuokkalaa, V. T. (2017) The role of microstructure in high stress abrasion of white cast irons, Wear, 388 – 389, 119 – 125, https://doi.org/10.1016/j.wear.2017.04.029
• Imurai, S., Thanachayanont, C., Pearce, J. T. H., Tsuda, K., Chairuangsri, T. (2014) Effects of Mo on microstructure of as-cast 28 wt.% Cr – 2.6 wt.% C – (0 – 10) wt.% Mo irons, Materials Characterization, 90, 99 – 112, https://doi.org/10.1016/j.matchar.2014.01.014
• Jacuinde, A. B., Rainforth, W. M. (2001) The wear behavior of high-chromium white cast irons as a function of silicon and mischmetal content, Wear, 250, 449 – 461, https://doi.org/10.1016/S0043-1648(01)00633-0
• Jokari – Sheshdeh, M., Ali, Y., Gallo, S. C., Lin, W., Gates, J. D. (2023) Effect of Cr-Fe ratio on the mechanical properties of (Cr,Fe)7C3 ternary carbides in abrasion-resistant white cast irons, Journal of Materials Science, 58, 7504 – 7521, https://doi.org/10.1007/s10853-023- 08461-z
• Jokari-Sheshdeh, M., Ali, Y., Gallo, S. C., Lin, W., Gates, J. D., (2022), Comparing the abrasion performance of Ni hard-4 and high-Cr-Mo white cast irons: the effects of chemical composition and microstructure, Wear, 492 – 493, 204208, https://doi.org/10.1016/j.wear.2021.204208
• Kadhim, M., Abood, A., Rabiha Y., (2011), The Role of Manganese on Microstructure of High Chromium White Cast Iron, Modern Applied Science, 5(1), https://doi.org/10.5539/mas.v5n1p179
• Lai, J. P., Pan, Q. L., Peng, H. J., Cui H. J., Xiao, C. A., (2016), Effects of Si on the microstructures and mechanical properties of high-chromium cast iron, Journal of Materials Engineering and Performance, 25, 4617 – 4623, https://doi.org/10.1007/s11665-016-2331-x
• Li, D., Liu, L., Zhang, Y., Ye, C., Ren, X., Yan, Y., Yang, Q., (2009), Phase diagram calculation of high chromium cast irons and influence of its chemical composition, Materials & Design, 30 (2), 340 – 345, https://doi.org/10.1016/j.matdes.2008.04.061
• Mourad, M., El – Hadad, S., Ibrahim, M. M., (2015), Effects of molybdenum addition on the microstructure and mechanical properties of Ni-Hard white cast iron, Trans Indian Ins. Met., 68 (5), 715 – 722, https://doi.org/10.1007/s12666-014-0504-6
• Nayak, U. P., Guitar, M. A., Mücklich, F., (2009), A comparative study on the influence of chromium on the phase fraction and elemental distribution in as-cast high chromium cast irons: simulation vs. experimentation, Metals, 10 (1), 30, https://doi.org/10.3390/met10010030
• Nayak, U. P., Schäfer, F., Mücklich, F., Guitar, M. A., (2023), Wear induced sub-surface deformation characteristics of a 26 wt.%Cr white cast iron subjected to a destabilization heat treatment, Tribology Letters, 71, 9, https://doi.org/10.1007/s11249-022-01683-3
• Ngqase, M., Pan, X., (2020), An overview on types of white cast irons and high chromium white cast irons, International Conference on Multifunctional Materials, 1495, 012023 https://doi.org/10.1088/1742-6596/1495/1/012023
• Purba, R. H., Kusumoto, K., Shimizu, K., Gaqi, Y., Huq, M. J., (2023), Influence of tempering temperature on abrasive-wear performance of high-chromium-based multicomponent white cast iron, Lubricants, 11 (7), 28, https://doi.org/10.3390/lubricants11070285
• Smallman, R.E. & Ngan, A.H.W. (1999). Modern physical metallurgy and materials engineering (6th ed.). Butterworth-Heinemann, Oxford, UK.
• Studnicki, A., Kilarski, J., Przybyl, M., Suchoń, J., Bartocha, D., (2006), Wear resistance of chromium cast iron-research and application, Journal of Achievements of Materials and Manufacturing Engineering, 16, 63 – 73.
• Yogenanadh, J., Natarajan, S., Babu S. P. K., (2013), Erosive wear behavior of nickel-based high alloy white cast iron under mining conditions using orthogonal array, Journal of Materials and Performance, 22 (9), 2534 – 2541, https://doi.org/10.1007/s11665-013-0539-6
• Zhang D., (2015), Characterisation and modelling of segregation in continuously cast steel slab, Thesis of Doctor of Philosophy, School of Metallurgy and Materials, College of Engineering and Physical Sciences The University of Birmingham. http://etheses.bham.ac.uk/id/eprint/6256.
• Zouch, F., Bahri, A., Antar, Z. (2023) Tribological performance of high chromium white cast iron and heat-treated steel used in barite crushing industry. Sci Rep 13, 9229 (2023). https://doi.org/10.1038/s41598-023-29627-4
• Zum Gahr K.-H., Doane, D. V., (1980), Optimizing fracture toughness and abrasion resistance in white cast irons, Metallurgical Transactions A, 11A, 613, https://doi.org/10.1007/BF02670698