İlyas UYGUR, Nursel ALTAN ÖZBEK, Fuat KARA, Onur ÖZBEK

Derin Kriyojenik İşlemin Kalıntı Gerilme ve Kalıntı Östenit Üzerindeki Etkisinin Araştırılması

Sıfırın altındaki sıcaklıklarda malzemelerin bekletilmesi olarak bilinen kriyojenik işlem, son yıllarda metal ve metal olmayan malzemelerin özelliklerini iyileştirmek için uygulanan bir yöntemdir. Bu yöntem daha çok kalıp yapımında kullanılan takım çelikleri için uygulanmaktadır. Ülkemizde, birçok özel sektör kuruluşu tarafından öncelikle kalıp malzemeleri olmak üzere birçok üründe kriyojenik işlem kullanımı yaygınlaşmaya devam etmektedir. Savunma sanayiinden otomotiv sanayiine kadar birçok sektörde bu işlemin faydaları kabul görmüştür. Bu çalışmada, geleneksel ısıl işlem uygulanmış (CHT) ve 24 saat derin kriyojenik işlem uygulanmış (DCT-24) Sleipner soğuk iş takım çeliğinin makro sertlik, mikro sertlik ve mikroyapı özellikleri incelenerek, malzemenin mekanik özellikleri ve mikroyapısındaki değişimler tespit edilmiştir. Bununla birlikte, X-Işını Kırınımı (XRD) Yöntemi ile malzemelerdeki kalıntı gerilme ve kalıntı östenit miktarları ölçülerek, numuneler arasındaki fark belirlenmiştir. CHT ve DCT-24 numunelerinin makro sertliği sırasıyla 60,96 HRC ve 61,46 HRC olarak ölçülmüştür. Mikro sertlik değerleri de sırasıyla 734,26 HV ve 761,83 HV olarak ölçülmüştür. Derin kriyojenik işlem makro ve mikro sertliği sırasıyla 0,5 HRC ve 27,57 HV arttırmıştır. Kalıntı östenit miktarı derin kriyojenik işlemden sonra % 36 oranında düşmüştür. Eksenel ve çevresel kalıntı gerilme değerleri de sırasıyla % 48,84 ve % 36,52 oranında düşmüştür. Sonuç olarak derin kriyojenik işlem Sleipner soğuk iş takım çeliğinin sertliği arttırmış, mikroyapıyı homojenleştirmiş, kalıntı östenit ve kalıntı gerilme değerlerini düşürerek olumlu iyileşmeler sağlamıştır.

Anahtar Kelimeler:

Sleipner, Kalıntı gerilme, Kalıntı östenit, Kriyojenik işlem

Investigation of the Effect of Deep Cryogenic Process on Residual Stress and Residual Austenite

The cryogenic treatment, known as holding materials at sub-zero temperatures, is a method used to improve the properties of metal and non-metallic materials in recent years. This method is mainly applied to tool steels used in mold making. In our country, the use of cryogenic processes continues to be widespread by many private sector organizations, primarily in mold materials. The benefits of this process have been recognized in many sectors, from the defense industry to the automotive industry. Sleipner cold work tool steel is widely used in blanking and fine blanking, shearing, forming, coining, cold forging, cold extrusion, thread rolling, drawing and deep drawing, powder pressing molds where high wear resistance, high chipping resistance and high compressive strength are required. In this study, the macro hardness, micro hardness and microstructure properties of Sleipner cold work tool steel, which was applied traditional heat treatment and deep cryogenic process for 24 hours, were examined and the changes in the mechanical properties and microstructure of the material were determined. However, by measuring the residual stress and residual austenite amounts in the materials with the X-Ray Diffraction (XRD) Method, the difference between the samples was determined. Deep cryogenic treatment increased the macro and micro hardness by 0.5 HRc and 27.57 HV, respectively. The amount of residual austenite decreased by 36% after deep cryogenic processing. Axial and circumferential residual stress values also decreased by 48.84% and 36.52%, respectively. As a result, the deep cryogenic process provided positive improvements by increasing the hardness of Sleipner cold work tool steel, homogenizing the microstructure, reducing the residual austenite and residual stress values.

Keywords:

Sleipner, Residual Stress, Retained Austenite, Cyrogenic Treatment,

PDF

___

[1] M. A. S. Bin Abdul Rahim, M. Bin Minhat, N. I. S. B. Hussein and M. S. Bin Salleh, “A comprehensive review on cold work of AISI D2 tool steel,” Metallurgical Research & Technology, vol. 115, pp. 104-116, 2018, https://doi.org/10.1051/metal/2017048. [2] B. Podgornik, M. Sedlaček, B. Žužek and A. Guštin, “Properties of tool steels and their importance when used in a coated system,” Coatings, vol. 10:3, pp. 1-17, 2020, https://doi.org/10.3390/coatings10030265.
[3] F. Kara, “Investigation of the effects of cryogenic treatment parameters on fatigue life and grindability of AISI 52100 steel,” Karabük University, Graduate School of Natural and Applied Sciences, Karabük, 2014.
[4] F. Kara, M. Karabatak, M. Ayyıldız and E. Nas, “Effect of machinability, microstructure and hardness of deep cryogenic treatment in hard turning of AISI D2 steel with ceramic cutting,” Journal of Materials Research and Technology, vol. 9:1, pp. 969-983, 2020, https://doi.org/10.1016/j.jmrt.2019.11.037.
[5] N. B. Dhokey, C. Thakur and P. Ghosh, “Influence of intermediate cryogenic treatment on the microstructural transformation and shift in wear mechanism in AISI D2 steel,” Tribology Transactions, vol. 64:1, pp. 91-100, 2021, https://doi.org/10.1080/10402004.2020.1804652.
[6] H. Zhang, X. Yan, Q. Hou and Z. Chen, “Effect of Cyclic Cryogenic Treatment on Wear Resistance, Impact Toughness, and Microstructure of 42CrMo Steel and Its Optimization,” Advances in Materials Science and Engineering, vol. 2021, pp. 1-13, 2021, https://doi.org/10.1155/2021/8870282.
[7] E. Demir and I. Toktas, “Effects of cryogenic treatment on residual stresses of AISI D2 tool steel,” Kovove Materialy, vol. 56, pp. 153-161, 2018, https://doi.org/10.4149/km20183153.
[8] P. I. Patil and R. G. Tated, “Comparison of effects of cryogenic treatment on different types of steels: A review,” International Journal of Computer Applications, vol. 9, pp. 10-29, 2012.
[9] A. Bensely, S. Venkatesh, D. Mohan Lal, G. Nagarajan, A. Rajadurai and K. Junik, “Effect of cryogenic treatment on distribution of residual stress in case carburized EN 353 steel,” Materials Science and Engineering: A, vol. 479:1-2, pp. 229-235, 2008, https://doi.org/10.1016/j.msea.2007.07.035.
[10] F. J. De Silva, S. D. Franco, A. R. Machado, E. O. Ezugwu and A. M. Souza Jr, “Performance of cryogenically treated HSS tools,” Wear, vol. 261:5-6, pp. 674-685, 2006, https://doi.org/10.1016/j.wear.2006.01.017.
[11] V. Leskovsek and B. Podgornik, “Vacuum heat treatment, deep cryogenic treatment and simultaneous pulse plasma nitriding and tempering of P/M S390MC steel,” Materials Science and Engineering: A, vol. 531, pp. 119-129, 2012, https://doi.org/10.1016/j.msea.2011.10.044.
[12] T. Vignesh Kumar, R. Thirumurugan and B. Viswanath, “Influence of cryogenic treatment on the metallurgy of ferrous alloys: A review,” Materials and Manufacturing Processes, vol. 32:16, pp. 1789-1805, 2017, https://doi.org/10.1080/10426914.2017.1317790.
[13] D. Das, A. K. Dutta, V. Toppo and K. K. Ray, “The Effect of cryogenic treatment on the carbide precipitation and tribological behavior of D2 steel,” Material and Manufacturing Processes, vol. 22:4, pp. 474-480, 2007, https://doi.org/10.1080/10426910701235934.
[14] H. S. Yang, J. Wang, B. Shen, H. H. Liu, S. J. Gao and S. J. Huang, “Effect of cryogenic treatment on the matrix structure and abrasion resistance of white cast iron subjected to destabilization treatment,” Wear, vol. 261:10, pp. 1150-1154, 2006, https://doi.org/10.1016/j.wear.2006.03.021.
[15] Z. Weng, X. Liu, K. Gu, J. Guo, C. Cui and J. Wang, “Modification of residual stress and microstructure in aluminium alloy by cryogenic treatment,” Materials Science and Technology, vol. 36:14, pp. 1547-1555, 2020, https://doi.org/10.1080/02670836.2020.1800182.
[16] M. Bicek, F. Dumont, C. Courbon, F. Pusaveca, J. Rech and J. Kopac, “Cryogenic machining as an alternative turning process of normalized and hardened AISI 52100 bearing steel,” Journal of Materials Processing Technology, vol. 212:12, pp. 2609-2618, 2012, https://doi.org/10.1016/j.jmatprotec.2012.07.022.
[17] J. Yi, W. J. Xue, Z. P. Xie, W. Liu, L. X. Cheng, J. Chen, H. Cheng and Y. X. Gao, “Enhanced toughness and hardness at cryogenic temperatures of silicon carbide sintered by SPS”, Materials Science and Engineering: A, vol. 569, pp. 13-17, 2013, https://doi.org/10.1016/j.msea.2013.01.053.
[18] A. Akhbarizadeh and S. Javadpour, “Investigating the effect of as-quenched vacancies in the final microstructure of 1.2080 tool steel during the deep cryogenic heat treatment,” Materials Letters, vol. 93, pp. 247-250, 2013, https://doi.org/10.1016/j.matlet.2012.11.081.