Karakteristik Sifat Mekanik dan Struktur Mikro Baja Laterit Paduan Ni-Cr-Mn Hasil Tempa Panas Dengan Variasi Beban Tempa [Mechanical Properties and Microstructure Characterization of Ni-Cr-Mn Alloys Lateritic Steel as a Result of Hot Forging with Variated
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Abstract
NiCrMn alloy lateritic steel has a potential as an alternative for steel raw material that has high toughness and substitute the commercial AISI 4340 steel. This research is conducted to know the characteristics of lateritic steels according to AISI 4340 standard from chemical composition, mechanical properties, and microstructure after hot forging process with variety of loads and oil as cooling media. The hot forging process was carried out at temperature of 1200 °C using 3 variety of forging loads: 50, 75, and 100 tons. The forged NiCrMn alloy lateritic steel was characterized by chemical composition analysis with OES (optical emission spectrometer), metallographic observation using OM (optical microscopy), Charpy impact test, and hardness Rockwell C. The result of chemical composition analysis showed that NiCrMn alloy lateritic steel had chemical composition in accordance to AISI 4340 with modification of Ni, Cr, and Mn elements equal to (wt.%) 1.8; 1.71; 1.87. The characteristics of NiCrMn alloy lateritic steel showed that the hardness and toughness increased when the % reduction improved. In reduction percentage of 31.02% it was obtained hardness value and energy absorb equal to 61.21 HRC and 0.166 J/mm2, with structure formed was martensit phase. However, at a higher reduction percentage of 31.72%, the hardness and impact strength values decreased to 58.56 HRC and 0.19 J/mm2. This occured because of the structure formed in the NiCrMn alloy lateritic steel was a martensite phase with retained austenite.
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References
W. Astuti, Z. Zulhan, A. Shofi, K. Isnugroho, F. Nurjaman, dan E. Prasetyo, “Pembuatan nickel pig iron (Npi) dari bijih nikel laterit indonesia menggunakan mini blast furnace,” Pros. InSINas, 2012, pp. 66-71.
E. Herianto, “Kupola udara panas untuk memproduksi NPI (nickel pig iron) dari bijih nikel laterit,” Maj. Metal., vol. 28, no. 2, pp. 121-130, 2013.
B. Bandanadjaja, “Modifikasi dan pengembangan baja komersial AISI 4340 menjadi baja tahan peluru,” J. PPT vol. viii, no. 1, pp. 669-680, 2010.
A. G. O. M. N. Bassim, “Shear strain localisation and fracture in high strength structural materials,” Manuf. Eng., vol. 31, no. 2, pp. 69-74, 2008.
H. Chen, D. Zhao, Q. Wang, Y. Qiang, dan J. Qi, “Effects of impact energy on the wear resistance and work hardening mechanism of medium manganese austenitic steel,” Friction, vol. 5, no. 4, pp. 447-454, 2017. doi: https://doi.org/10.1007/s40544-017-0158-6
P. K. Jena, P. S. P, dan S. K. K., “Effect of tempering time on the ballistic performance of a high strength armour steel,” Rev. Mex. Trastor. Aliment., vol. 14, no. 1, pp. 47-53, 2016. doi: 10.1016/j.jart.2016.02.002
Yusuf dan E. Herianto, “Pembuatan besi nugget dari pasir besi dan bijih besi laterit: tantangan dan kemungkinan keberhasilannya,” Maj. Metal., vol. 23, no. 2, pp. 25-29, 2008.
B. M. Gurumurthy, Y. M. Shivaprakash, G. S. M. C, S. S. Sharma, dan A. Kini, “Comparative studies on mechanical properties of AISI 4340 high-strength alloy steel under time-quenched and austempered conditions,” International Journal of Research in Engineering and Technology, no. 4, pp. 530-535, 2015.
S. Herbirowo, B. Adjiantoro, dan T. B. Romijarso, “Effects of austenitizing and forging on mechanical properties of MIL A-12560/AISI 4340 steel,” IOP Conf. Ser. Mater. Sci. Eng., 2017, vol. 202, p. 12084. doi: 10.1088/1757-899X/202/1/012084
S. H. Atapek, “Development of a new armor steel and its ballistic performance,” Def. Sci. J., vol. 63, no. 3, pp. 271-277, 2013. doi: 10.14429/dsj.63.1341
M. Jahazi dan B. Eghbali, “The influence of hot forging conditions on the microstructure and mechanical properties of two microalloyed steels,” J. Mater. Process. Technol., vol. 113, pp. 594–598, 2001. doi: 10.1016/s0924-0136(01)00599-4
D. Jeddi dan H. P. Lieurade, “Effect of retained austenite on high cycle fatigue behavior of carburized 14NiCr11 steel,” Procedia Eng., vol. 2, no. 1, pp. 1927-1936, 2010. doi: 10.1016/j.proeng.2010.03.207
ASTM A 370, "Standard test methods and definitions for mechanical testing of steel products,” A10.13, pp.18-25, 1992.
Steel and tube, “High tensile steel-AISI 4340,” stainless.steelandtube.co.nz.,2012. [Online] Available: http://stainless.steelandtube.co.nz/wp-content/uploads/2014/06/HighTensileSteel4340.pdf. [Accessed: 13 Maret, 2018].
O. Bogdan, “Numerical analysis of casting technology and a-segregation prediction in AISI 4340 forgings products 1 introduction 2 the mathematical model to simulate the solidification process,” Industrial Soft Pub, pp. 1-12, 2010.
S. V. Sajadifar, G. G. Yapici, M. Ketabchi, dan B. Bemanizadeh, “High temperature deformation behavior of 4340 steel: Activation energy calculation and modeling of flow response,” J. Iron Steel Res. Int., vol. 20, no. 12, pp. 133-139, 2013. doi: https://doi.org/10.1016/S1006-706X(13)60226-5
H. Hou, L. Qi, dan Y. H. Zhao, “Effect of austenitizing temperature on the mechanical properties of high-strength maraging steel,” Materials Science and Engineering A, vol. 587, pp. 209-212, 2013. doi: https://doi.org/10.1016/j.msea.2013.08.070
S. Herbirowo dan B. Adjiantoro, “Characteristic of mechanical and morphological properties of hot rolled laterite steel with variety of size reduction,” Solid State Phenom., vol. 266, pp. 8-12, 2017. doi: https://doi.org/10.4028/www.scientific.net/SSP.266.8
M. Y. Hasbi, D. P. Malau, dan B. Adjiantoro, “Pengaruh variasi reduksi terhadap kekerasan dan strukturmikro baja laterit melalui pengerolan panas,” Pros. Semnastek, no.1, 2016, pp. 1-8.
G. R. Ebrahimi dan M. Javdani, “Effect of thermo-mechanical parameters on microstructure and mechanical properties of microalloyed steels,” Brazilian J. Phys., vol. 40, no. 4, pp. 454-458, 2010.
H. Karbasian dan A. E. Tekkaya, “A review on hot stamping,” J. Mater. Process. Technol., vol. 210, no. 15, pp. 2103-2118, 2010. doi: 10.1016/j.jmatprotec.2010.07.019
P. Taylor, A. Babakhani, dan S. M. R. Ziaei, “The microstructure and mechanical properties of hot forged vanadium microalloyed steel,” Materials and Manufacturing Processes, vol. 27, no. 2, pp. 135-139, 2012. doi: https://doi.org/10.1080/10426914.2011.557287
