INVESTIGATING THE EFFECT OF HEAT TREATMENT ON THE COLD FORGING OF 27MNB4 STEEL VIA CALPHAD METHODOLOGY AND FEM

Yıl 2023, , 59 - 70, 01.03.2023

Yağız Akyıldız , Ümit Kutsal , Yağız Arslan , Adnan Akman , Atıf Karkınlı , Mert Saglam , Rıdvan Yamanoğlu

https://doi.org/10.36306/konjes.1130504

Öz

As a material forming method, cold forging is preferred due to the reasons like absence of a heating step and high surface quality. Recently, the finite element method (FEM) has received growing attention for controlling and predicting final material properties for cold forging applications. FEM combines microstructure evolution models with failure criteria, thus providing solutions to complicated problems in the modern cold forging industry. The fastener industry extensively utilizes cold forging, in which manganese and boron-containing steels like 27MnB4 can be formed to obtain high mechanical properties. The current study investigates the effect of two different heat treatments, namely softening and spheroidizing annealing, on the formability of 27MnB4 bolts. Softwares such as Thermo-Calc 2022a and Forge NxT 3.2 were used to predict the microstructure of the wire rod and evaluate the cold forming process of the same rod under two different heat treatment conditions. Therefore, the current study also provides a relationship between microstructural features and the cold formability of 27MnB4 steel. The microstructure of 27MnB4 is predicted by CCT diagrams. The predicted microstructure corresponds to the microstructure of 27MnB4 samples taken from the production line. In addition, temperature, von Mises stress, and equivalent strain distributions for 27MnB4 steel in the hot rolled state were calculated higher than in annealed states due to the differences in the microstructure. These results demonstrate that computational material engineering methods and simulation techniques could be practical tools for cold forming processes.

Anahtar Kelimeler

27MnB4, Cold forming, Finite element method, Forging simulation, Computational materials Engineering

27MnB4 Çeliğinin Soğuk Dövülmesinde Isıl İşlem Etkisinin Calphad ve Sonlu Elemanlar Yöntemi ile İncelenmesi

Öz

Malzeme şekillendirme yöntemi olarak soğuk dövme, ısıtma adımının olmaması ve yüksek yüzey kalitesi bakımından tercih edilir. Sonlu elemenlar metodolojisi ise son zamanlarda soğuk dövme prosesinde malzeme özelliklerinin kontrolü ve tahmin edilmesi noktalarında popüler olmuştur. Sonlu elemanlar yöntemi, mikroyapı ve hata kriteri modellerini birleştirerek dövme endüstrisindeki karmaşık sorunlara çözüm sunabilmektedir. Bağlantı elemanları sektörü soğuk dövmenin en sık kullanıldığı alanlardandır. 27MnB4 borlu çeliği ise civata endüstrisinde sıklıkla kullanılan çelik kalitlerindendir. Bu çalışmada iki farklı ısıl işlemin, yumuşatma ve küreselleştirme tavlaması, çelik civatanın şekillendirebilirliği üzerine etkisi incelenmiştir. Tavlama işlemlerinin etkisi, 27MnB4 çelik civatanın soğuk dövülmesinin Thermo-Calc 2022a versiyonu ve sonlu elemanlar yazılımı olan Forge NxT 3.2 versiyonu kullanılarak ortaya konmuştur. Bu çalışma, 27MnB4 çeliğinin mikroyapısı ve şekillendirilebilirliği arasında bağlantı kurmaktadır. Sıcak haddelenmiş numunelerde tavlanmış numunelere göre mikroyapısal farklılıklar sebebiyle daha yüksek sıcaklıklar, von Mises gerilimleri ve gerinimler gözlenmiştir.

Anahtar Kelimeler

27MnB4 Çeliği, Soğuk Dövme, Sonlu Elemanlar Metodu, Forge NxT, Thermo-Calc

Kaynakça

• [1] H. C. Lee, Y. G. Jin, Y. H. Lee, I. H. Son, D. L. Lee, Y. T. Im, ‘’Process design of high-strength bolt of fully pearlitic high-carbon steel,’’ Journal of Materials Processing Technology, vol. 210, no. 14, pp. 1870-1875, 2010.
• [2] A. Lindemann and J. Schmidt, ‘’ACMOD-2D—a heat transfer model for the simulation of the cooling of Wire Rod,’’ Journal of Materials Processing Technology, vol. 169, no. 3, pp. 466–475, 2005.
• [3] D. Y. Wu, F. R. Xiao, B. Wang, J. L. Liu, ‘’Investigation on grain refinement and precipitation strengthening applied in high speed wire rod containing vanadium,’’ Materials Science and Engineering: A, vol. 592, pp. 102-110, 2014.
• [4] V. Javaheri, T. Nyyssönen, B. Grande, D. Porter, ‘’Computational design of a novel medium-carbon, low-alloy steel microalloyed with niobium,’’ Journal of Materials Engineering and Performance, vol. 27, no. 6, pp. 2978–2992, 2018.
• [5] R. Jha and G. S. Dulikravich, ‘’Solidification and heat treatment simulation for aluminum alloys with scandium addition through CALPHAD approach,’’ Computational Materials Science, vol. 182, no. 109749, 2020.
• [6] Y. Akyıldız, O. Öztürk and B. Simsar, ‘’Al-10Si-xMg Alaşımının CALPHAD Metodolojisi ile Termodinamik Karakterizasyonu,’’ Süleyman Demirel Üniversitesi Fen Bilimleri Enstitüsü Dergisi, vol. 25, no. 3, pp. 699-704, 2021.
• [7] S. Y. Hsia, and Y. T. Chou, ‘’Fabrication improvement of cold forging hexagonal nuts by computational analysis and experiment verification,’’ Mathematical Problems in Engineering, 2015.
• [8] R. Rajiev, P. Sadagopan, R. S. Prakash, ‘’Study on investigation of hot forging die wear analysis–An industrial case study,’’ Materials Today: Proceedings, vol. 27, pp. 2752-2757, 2020.
• [9] Z. Li, D. Wu, W. Lv, ‘’Study on the crack forming during cold forging process of ML25Mn steel, ’’Applied Mechanics and Materials, vol. 184, pp. 1255-1258, 2012.
• [10] H. Bhadeshia, H and R. Honeycombe, Steels: Microstructure and Properties, ch. 6. Elsevier, 4nd ed., Kidlington, UK, Elsevier, 2017. [E-book] Available: Safari e-book.
• [11] H. C. Lee, M. A. Saroosh, Y. T. Im, H. S. Kim, I. H. Son, D. L. Lee, ‘’Two-dimensional finite element approximation of the hexagonal bolt forming process,’’ Journal of Materials Processing Technology, vol. 201, pp. 19-24, 2008.
• [12] S. Chen, Y. Qin, C. M. Choy, J. G. Chen, ‘’Testing an injection forging process for the production of automotive fasteners,’’ Procedia engineering, vol. 207, pp. 508-513, 2017.
• [13] S. Narita, K. Hayakawa, T. Uemori, Y. Kubota, ‘’Evaluation of strength of stainless steel bolt without heat treatment considering Bauschinger effect during manufacturing process,’’ Journal of Materials Processing Technology, vol. 278, 2020.
• [14] S. Orhan, F. Öztürk, J. Gattmah, ‘’Effects of the semi die/plug angles on cold tube drawing with a fixed plug by FEM for AISI 1010 steel tube,’’ Sakarya Üniversitesi Fen Bilimleri Enstitüsü Dergisi, vol. 21 no. 5, pp. 886-892, 2017.
• [15] P. Dai, Y. Wang, S. Li, S. Lu, G. Feng, D. Deng, ‘’FEM analysis of residual stress induced by repair welding in SUS304 stainless steel pipe butt-welded joint,’’ Journal of Manufacturing Processes, vol. 58, pp. 975-983, 2020.
• [16] Z. Li and D. Wu, ‘’Study of the high strength and low yield ratio cold forging steel,’’ Materials Science and Engineering: A, vol. 452, pp. 142-148, 2007.
• [17] D. Petrescu, S. C. Savage, P. D. Hodgson, ‘’Simulation of the fastener manufacturing process,’’ Journal of Materials Processing Technology, vol. 125-126, pp. 361–368, 2002.
• [18] N. Y. Ben, Q. Zhang, D. W. Zhang, ‘’Improvement of axial forging process for spline shaft by die design,’’ The International Journal of Advanced Manufacturing Technology, vol. 99, pp. 2727-2741, 2018
• [19] C. Kiener, M. Merklein, ‘’Research of adapted tool Design in Cold Forging of gears,’’ International Journal of Material Forming, vol. 13 no. 6, pp. 873-883, 2020.
• [20] S. F. Di Martino and G. Thewlis, ‘’Transformation characteristics of ferrite/carbide aggregate in continuously cooled, low carbon-manganese steels,’’ Metallurgical and Materials Transactions A, vol. 45, no. 2, 579–594, 2013.
• [21] B. T. Tang, Q. L. Wang, S. Bruschi, A. Ghiotti, P. F. Bariani, ‘’Influence of temperature and deformation on phase transformation and Vickers hardness in tailored tempering process: Numerical and experimental verifications,’’ Journal of Manufacturing Science and Engineering, vol 136, no. 5, 2014.
• [22] C. C. Yang and C. L. Liu, ‘’Optimization of Spheroidized Process Parameters for Two AISI 1022 Steel Wires Using Taguchi Approach,’’ International Journal of Mechanical Engineering and Mechatronics (IJMEM), vol. 4 no. 1, pp. 1-11, 2017.
• [23] J. I. Cheng, W. A. N. G. Lei, M. Y. Zhu, ‘’Effect of subcritical annealing temperature on microstructure and mechanical properties of SCM435 steel,’’ Journal of Iron and Steel Research, International, vol. 22 no. 11, pp. 1031-1036, 2015.
• [24] M. C. Sun, G. Y. Tzou, L. A. Zheng, ‘’Study on multi-stage cold forging of stainless automotive battery fastener,’’ Applied Mechanics and Materials vol. 284, pp. 211-215, 2013.
• [25] U. C. Chai, G. Y. Tzou, C. M. Hsu, S. P. Wei, ‘’FEM simulation of multi-stage forging for dray fasteners,’’ Key Engineering Materials vol. 830, pp. 1-8, 2020.