Elektrik direnç punta kaynağı ile kaynak edilmiş TWIP çeliklerinde kaynak parametrelerinin Taguchi yöntemi ile optimizasyonu

Öz

Bu çalışmanın amacı, TWIP çelik saclarının elektrik direnç punta kaynağı ile birleştirmelerinde Taguchi metodu kullanarak kaynak parametrelerinin optimize edilmesidir. Kaynak akımı, kaynak zamanı ve elektrot baskı kuvveti gibi kaynak parametrelerinin değerleri, rastgele yaklaşımlı L9 Taguchi ortogonal dizine göre belirlenmiştir. Optimum kaynak parametreleri, kaynaklı numunelerin en yüksek kopma yüküne göre tahmin edilmiş ve her bir parametrenin kopma yükü üzerindeki etkisi sinyal/gürültü (S/N) oranı ve varyans analizi (ANOVA) ile değerlendirilmiştir. Optimum kaynak akımı, kaynak zamanı ve elektrot kuvveti sırasıyla 12 kA, 300 ms and 3000 N olarak bulunmuştur. ANOVA sonuçları, kopma yükü üzerindeki en yüksek istatiksel etkiye %78.73 ile kaynak akımının sahip olduğunu gösterirken, kaynak akımını da sırasıyla kaynak zamanı ve elektrot baskı kuvvetinin takip ettiğini göstermiştir. Elektrik direnç punta kaynağı ile kaynak edilmiş birleştirmelerin kopma yükleri kaynak akımı ve elektrot baskı kuvvetiyle artmıştır. Ancak, yüksek kaynak zamanlarında nispeten daha düşük kopma yükleri gözlenmiştir. Ayrıca, seçilen kaynaklı numunelerin kırılma yüzeyleri taramalı elektron mikroskobu (SEM) kullanılarak karakterize edilmiştir. Bu incelemede, daha yüksek kaynak mukavemetine sahip birleştirmelerin nispeten daha sünek kırılma karakteristiği sergilediği görülmüştür.

Anahtar Kelimeler

• TWIP çeliği,Elektrik direnç punta kaynağı,Kaynak parametreleri,Kaynak mukavemeti,Optimizasyon

The optimisation of welding parameters for electrical resistance spot-welded TWIP steels using a Taguchi method

Abstract

The aim of this work is to optimize the welding parameters of electrical resistance spot welded TWIP steel sheets using a Taguchi method. The welding parameters, such as weld current, welding time and electrode force, were determined according to the Taguchi orthogonal array L9 using a randomized approach. The optimum welding parameters for the peak tensile shear load of the joints were predicted, and the individual importance of each parameter on the tensile shear load of the resistance spot weld was evaluated by examining the signal-to-noise (S/N) ratio and analysis of variance (ANOVA). The optimum weld current, welding time and electrode force were found to be 12 kA, 300 ms and 3000 N, respectively. The ANOVA results indicated that the weld current has the highest statistical effect with 78.73% on the tensile shear load, followed by the welding time and electrode force. The tensile shear load of the resistance spot welding joints increased with increasing weld current and electrode force. But, higher welding time led to relatively lower tensile shear load. In addition, the fracture surface characterization of the selected joints was conducted using scanning electron microscopy (SEM) technique. In this examination, it has been found that the joints having higher weld strength exhibited a relatively more ductile fracture characteristic.

Keywords

• TWIP steel,Electrical resistance spot welding,Welding parameters,Weld strength,Optimisation.

Kaynakça

1. Bouaziz O, Allain S, Scott CP, Cugy P, Barbier D. "High manganese austenitic twinning induced plasticity steels: A review of the microstructure properties relationships". Current Opinion in Solid State & Materials Science, 15, 141-168, 2011.
2. Chen L, Zhao Y, Qin, X. "Some aspects of high manganese twinning-induced plasticity (TWIP) steel, a review". Acta Metallurgica Sinica (English Letters), 26, 1-15, 2013.
3. Cornette D, Cugy P, Hildenbrand A, Bouzekri, M, Lovato G. "Ultra High Strength FeMn TWIP Steels for Automotive Safety Parts". SAE Technical Paper 2005-01-1327, 2005, https://doi.org/10.4271/2005-01-1327.
4. Curtze S, Kuokkala VT. "Dependence of tensile deformation behavior of TWIP steels on stacking fault energy, temperature and strain rate". Acta Materialia, 58(15), 5129-5141, 2010.
5. Peng X, Zhu D, Hu Z, Wang M, Liu L, Liu H. "Effect of carbon content on stacking fault energy of Fe-20Mn-3Cu TWIP Steel". Journal of Iron and Steel Research, International, 21(1), 116-120, 2014.
6. Xiong Z, Ren X, Shu J, Wang Z, Bao W, Li, S. "Effect of Temperature on Microstructure and Deformation Mechanism of Fe-30Mn-3Si-4Al TWIP Steel at Strain Rate of 700 s−1". Journal of Iron and Steel Research, International, 22(2), 179-184, 2015.
7. Neu RW. "Performance and characterization of TWIP steels for automotive applications". Materials Performance and Characterization, 2(1), 244-284, 2013.
8. Saha DC, Cho Y, Park Y. "Metallographic and fracture characteristics of resistance spot welded TWIP steels" Science and Technology of Welding and Joining, 18(8), 711-720, 2013.

9. Ma L, Wei Y, Hou L, Yan B. "Microstructure and mechanical properties of TWIP steel joints". Journal of Iron and Steel Research, International, 21(8), 749-756, 2014.
10. Jin JE, Lee YK. "Strain hardening behavior of a Fe-18Mn-0.6C-1.5Al TWIP steel". Materials Science and Engineering: A, 527(1-2), 157-161, 2009.
11. Billur E, Cetin B, Gurleyik M. “New generation advanced high strength steels: developments, trends and constraints”. International Journal of Scientific and Technological Research, 2(1), 50-62, 2016.
12. Saha DC, Han S, Chin KG, Choi I, Do Park Y. "Weldability evaluation and microstructure analysis of resistance-spot- welded high-Mn steel in automotive application". Steel Research International, 83(4), 352-357, 2012.
13. Saha DC, Chang I, Park Y-D. “Heat-affected zone liquation crack on resistance spot welded TWIP steels”. Materials Characterization, 93, 40-51, 2014.
14. Mújica Roncery L, Weber S, Theisen W. “Welding of twinning-induced plasticity steels”. Scripta Materialia, 66(12), 997-1001, 2012.
15. Yu J, Shim J, Rhee S. “Characteristics of resistance spot welding for 1 GPa grade twin ınduced plasticity steel”. Materials Transactions, 53(11), 2011-2018, 2012.
16. Holovenko O, Lenco MG, Pastore E, Pinasco MR, Matteis P, Scavino G, Firrao D. "Microstructural and mechanical characterization of welded joints on innovative high-strength steels". Metallurgia Italiana, 105(3), 3-12, 2013.
17. Spena PR, Matteis P, Sanchez A, Scavino G. "Strength and fracture of TWIP steel dissimilar weld joints". Convegno Nazionale IGF XXII, Roma, Italia, 1-3 July 2013, 109-117
18. Razmpoosh M, Shamanian M, Esmailzadeh M. "The microstructural evolution and mechanical properties of resistance spot welded Fe - 31Mn - 3Al - 3Si TWIP steel". Materials and Design, 67, 571-576, 2015.
19. Tutar M, Aydın H, Yüce C, Yavuz N, Bayram A. “The optimisation of process parameters for friction stir spot-welded AA3003-H12 aluminium alloy using a Taguchi orthogonal array”. Materials & Design, 63, 789-797, 2014.
20. Singh NK, Vijayakumar Y. "Application of Taguchi method for optimization of resistance spot welding of austenitic stainless steel AISI 301L". Innovative Systems Design and Engineering, 3(10), 49-61, 2012.
21. Thakur AG, Rao TE, Mukhedkar MS, Nandedkar VM. "Application of Taguchi method for resistance spot welding of galvanized steel". ARPN Journal of Engineering and Applied Sciences, 5(11), 22-26, 2010.
22. Raut M, Achwal V. "Optimization of spot welding process parameters for maximum tensile strength". International Journal of Mechanical Engineering and Robotics Research, 3(4), 507-517, 2014.
23. Pandey AK, Khan MI, Moeed KM. "Optimization of resistance spot welding parameters using Taguchi Method". International Journal of Engineering Science and Technology, 5(2), 234-241, 2013.
24. Thakur AG, Nandedkar VM. "Optimization of the resistance spot welding process of galvanized steel sheet using the Taguchi method". Arabian Journal for Science and Engineering, 39(2), 1171-1176, 2014.
25. Tutar M, Aydin H, Bayram A. "Multi objective Taguchi optimization approach for resistance spot welding of cold rolled TWIP steel sheets". IOP Conf. Series: Journal of Physics: Conf. Series, 885, 1-5, 2017.
26. ASTM E8/E8M standard test methods for tension testing of metallic materials. Annual Book of ASTM Standards 4, 1-27, 2010.
27. Ertek Emre H, Kaçar R. "Resistance spot weldability of galvanize coated and uncoated TRIP steels”. Metals, 6, 299, 2016. doi:10.3390/met6120299.
28. Baskoro AS, Trianda MR, Istiyanto J, Supriyadi S, Sumarsono DA, Kiswanto G. “Effects of welding time and welding current to weld nugget and shear load on electrical resistance spot welding of cold rolled sheet for body construction”. IEEE International Conference on Electrical Engineering and Computer Science, Bali, Indonesia, 24-25 November 2014.
29. Tutar M, Aydin H, Bayram A. “Effect of Weld Current on the Microstructure and Mechanical Properties of a Resistance Spot-Welded TWIP Steel Sheet”. Metals, 7, 519, 2017.
30. Aydin H, Tutar M, Bayram A. “The Influence of Welding Time on Mechanical Properties of Resistance Spot Welded TWIP Steel Sheets”. XIII International Scientific Congress Machines, Technologies, Materials, Varna, Bulgaria, 14-17 September 2016.
31. Aydin H, Tutar M, Bayram A. “Otomotiv sanayinde kullanılan twıp çeliğinin elektrik direnç punta kaynağında elektrod baskı kuvvetinin mekanik özelliklere etkisi”. 8. Otomotiv Teknolojileri Kongresi OTEKON16, Bursa, Türkiye, 23-24 Mayıs 2016.