INVESTIGATION OF MACHINABILITY OF COOLED MICROALLOY STELL IN OIL AFTER THE HOT FORGING WITH COATED AND UNCOATED CBN CUTTING TOOLS

Year 2018, Volume: 36 Issue: 4, 1165 - 1174, 01.12.2018

Barış Özlü Halil Demir Mustafa Türkmen Süleyman Gündüz

Abstract

The aim of this study was to investigate the cutting forces and surface roughness of 38MnVS6 microalloyed steel quenched in oil following hot forging. The machinability tests were carried out by turning under dry cutting conditions using coated and uncoated cubic boron nitride (CBN) cutting tools at five different cutting speeds (120, 150, 180, 210 and 240 m / min), a constant feed rate (0.04 mm / rev) and a constant chip depth (0.6 mm). The microalloyed steel used in the experimental study was optically examined and a hardness test was applied. Scanning electron microscopy (SEM) was used to evaluate the wear on the cutting tools. The findings for the 38MnVS6 steel which was oil quenched after forging showed that due to the high cooling rate, a martensite structure had been formed and the hardness value was high. The lowest surface roughness values of 0.367 μm and 0.164 μm were obtained at a cutting speed of 180 m / min with the coated and the uncoated CBN cutting tools, respectively. In the turning experiments, the surface roughness values measured using the coated CBN cutting tool were about 103% higher than those measured using the uncoated CBN cutting tool and the highest cutting forces were obtained at a cutting speed of 120 m / min.

Keywords

Hot forging, microalloyed steel, machinability, CBN cutter.

References

• ⦁ Chen S.L., Hui W.J., Wang L.H., Dai G.W., Dong H., (2014) Research and development of energy-saving high performance microalloyed forging steels, Iron and Steel, 49 (6), 1-7.
• ⦁ Salleh, T. S., Nishida, S-i., Hattori N., (2004) Influence of microalloyed elements and ion nitriding on fatigue properties of ultra-low carbon steel sheets,  ⦁ Strength, Fracture and Complexity, 2 (2), 69-80.
• ⦁ Ghosh A., Das S., Chatterjee S., Ramachandra R.P, (2006) Effect of cooling rate on structure and properties of an ultra-low carbon HSLA-100 grade steel, Materials Characterization, 56, 59-65.
• ⦁ Ghosh A., Mishra B., Das S., Chatterjee S., (2005) Microstructure, properties and age hardening behaviour of a thermo-mechanically processed ultra low carbon Cu bearing high strength steel, Metallurgical and Materials Transaction, 36, 703-713.
• ⦁ Al-Zkeri, İ.A., (2007) Finite element modeling of hard turning, Doctoral Thesis, The Ohio State University.
• ⦁ Ng E., Aspinwall D.K., (2002), The effect of workpiece hardness and cutting speed on the machinability of AISI H13 hot work die steel when using PCBN tooling, Trans. ASME J. Manuf. Sci. Eng., 124, 582-594.
• ⦁ Aouici H., Yallese M.A., Chaui K., Mabrouki T., Rigal J.F., (2012), Analysis of surface roughness and cutting force components in hard turning with CBN tool: Prediction model and cutting conditions optimization, ⦁ Measurement, ⦁ 45, (3), 344-353.
• ⦁ Huang Y., Liang S.Y., (2005), Modeling of cutting forces under hard turning conditions considering tool wear effect, Trans. ASME J. Manuf. Sci. Eng., 127, 262-270.
• ⦁ Lima J.G., Avila R.F., Abrao A.M., Faustino M., Davim J.P., (2005), Hard turning: AISI 4340 high strength low alloy steel and AISI D2 cold work tool steel, J. Mater. Process. Technol., 169, 388-395.
• ⦁ Arsecularatne J.A., Zhang L.C., Montross C., Mathew P., (2006), On machining of hardened AISI D2 steel with PCBN tools, J. Mater. Process. Technol., 171, 244-252.
• ⦁ Elbah ⦁ M., Yallese A.⦁ M., Aouici ⦁ H., Mabrouki ⦁ T., Rigal ⦁ J.F., (2013), Comparative assessment of wiper and conventional ceramic tools on surface roughness in hard turning AISI 4140 steel, ⦁ Measurement, ⦁ 46, (9)3041-3056.
• ⦁ Demir H., Özlü B., (2009), An investigation into the machinability of 30MnVS6 microalloyed steels based on cutting forces and surface roughness, Erciyes University Journal of Institute of Science and Technology, 25 (1-2), 262-271.
• ⦁ Shihab K.S., Khan A.Z., Mohammad A., Siddiquee N.A., (2014), A review of turning of hard steels used in bearing and automotive applications, Production & Manufacturing Research, 2 (1), 24-49.
• ⦁ Palanisamy D., Senthil P., (2018), A comparative study on machinability of cryo-treated and peak aged 15Cr5Ni precipitation hardened stainless steel, ⦁ Measurement, ⦁ 116, 162-169.
• ⦁ Demir H., (2008), The effects of microalloyed steel pre-heat treatment on microstructure and machinability, Int. J. Adv. Manuf. Technol., 35, 1041-1046.
• ⦁ Savaşkan, T.(1999) Material Information and Examination, KTÜ, Trabzon.
• ⦁ Tekin A., (1984), Steel and Heat Treatment, İTÜ, İstanbul.
• ⦁ Bergman G., (1999) Modeling and simultaneous forming and quenching, Doctoral Theses, Lulea University of Technology, Schweden.
• ⦁ Zhoua J., Bushlyaa V., Avdovic P., Stahla J.E., (2012), Study of surface quality in high speed turning of Inconel 718 with uncoated and coated CBN tools, Int J Adv Manuf Technol, 58, 141-151.
• ⦁ Basavarajappa S., Suresh R., Gaitonde ⦁ V.N., Samuel G.L., (2014), Analysis of cutting forces and surface roughness in hard turning of AISI 4340 using multilayer coated carbide tool, Int. J. Machining and Machinability of Materials, 16 (2), 169-185.
• ⦁ Çiçek A., Kara F., Kıvrak T., Ekici E., (2013), Evaluation of machinability of hardened and cryo-treated AISI H13 hot work tool steel with ceramic inserts, Int. J. Refractory Metals Hard Mater. 41, 461-469.
• ⦁ Ranganathan S., Senthilvelan T., Sriram G., (2010), Evaluation of machining parameters of hot turning of stainless steel (Type 316) by applying ANN and RSM, Materials and Manufacturing Processes, 25, 1131-1141.
• ⦁ Ferreira R., Carou D., Lauro C.H., Davim J.P., (2016), Surface roughness investigation in the hard turning of steel using ceramic tools, Mater Manuf Process, 31 (5), 648-665.
• ⦁ Demir H., Gündüz S., (2009), The effects of aging on machinability of 6061 aluminium alloy, Materials and Design, 30, 1480-1483.
• ⦁ Shaw M.C., (1984), Metal Cutting Principles, ⦁ Oxford Series on Advanced Manufacturing Press, London.