CORROSION BEHAVIOUR OF TEMPERED 42CrMo4 STEEL
Low-alloy 42CrMo4 steel (AISI 4140) is a medium carbon steel, commonly used as a quenched and tempered steel. Because of its good mechanical properties, high tensile strength and toughness, 42CrMo4 is one of the widely used and investigated steels. In order to increase ductility even more, in addition to standard quenching and tempering, steel is often hardened by double quenching and tempering and austempering. The aim of this paper was to investigate the corrosion behaviour of 42CrMo4 steel after quenching and tempering, double quenching and tempering and austempering. For this purpose, microstructural characterization and electrochemical investigation after different hardening processes were performed. Microstructure of specimens was observed using optical microscopy and scanning electron microscopy. Open circuit potential and potentiodynamic polarization measurements of tempered specimens were carried out using computer-controlled potentiostat with three electrode set-up in 0.6 M NaCl naturally aerated solution. It was concluded that applied heat treatment processes increase the corrosion resistance of 42CrMo4 steel in comparison to normalized steel. In comparison to quenched and tempered steel, double quenching and tempering, as well as austempering, do not significantly change corrosion resistance of steel.
2 S. Smokvina Hanza, Mathematical Modeling and Computer Simulation of Microstructure Transformations and Mechanical Properties during Steel Quenching (in Croatian), Ph.D. thesis, University of Rijeka, Rijeka, Croatia, 2011.
3 Dario Iljkić, A Contribution to the Development of the Mechanical Properties Prediction of Quenched and Tempered Steel and Cast Steel (in Croatian), Ph.D. thesis, University of Rijeka, Rijeka, Croatia, 2010.
4 F. Zhu, X. Luo, F. Chai, C. Yang, Z. Zhang, Effect of double quenching and tempering temperature on the microstructure and mechanical properties of a High Strength Low Alloy Steel, IOP Conf. Series: Materials Science and Engineering, 772 (2020), doi: 10.1088/1757-899X/772/1/012010
5 J. Liu, H. Yu, T. Zhou, C. Song, K. Zhang, Effect of double quenching and tempering heat treatment on the microstructure and mechanical properties of a novel 5Cr steel processed by electro-slag casting, Materials Science & Engineering A, 619 (2014), 212-220, doi: 10.1016/j.msea.2014.09.063
6 M.H. Khani Sanij, S.S. Ghasemi Banadkouki, A.R. Mashreghi, M. Moshrefifar, The effect of single and double quenching and tempering heat treatments on the microstructure and mechanical properties of AISI 4140 steel, Materials and Design, 42 (2012), 339–346, doi: 10.1016/J.MATDES.2012.06.017
7 G.E. Totten, editor, Steel Heat Treatment: Metallurgy and Technologies, 2nd ed., CRC Press, Taylor & Francis Group, 2007.
8 D. E.J. Talbot, J. D.R. Talbot, Corrosion Science and Technology, 3rd ed., CRC Press, Taylor & Francis Group, 2018.
9 B. Smoljan, D. Iljkić, S. Smokvina Hanza, M. Jokić, L. Štic, A. Borić, Mathematical Modeling and Computer Simulation of Steel Quenching, Materials Performance and Characterization, 8 (2019) 2, 17-36, doi: 10.1520/MPC20180040
10 A. Çalık, O. Dokuzlar, N. Uçar, The effect of heat treatment on mechanical properties of 42CrMo4 steel, Journal of Achievements of Materials and Manufacturing Engineering, 1 (2020) 98, 5-10, doi: 10.5604/01.3001.0014.0811
11 W.-S. Lee, T.-T. Su, Mechanical properties and microstructural features of AISI 4340 high-strength alloy steel under quenched and tempered conditions, Journal of Materials Processing Technology, 87 (1999), 198–206, doi: 10.1016/S0924-0136(98)00351-3
12 Z. Ahmad, Principles of Corrosion Engineering and Corrosion Control, Elsevier, 2006.
13 Y. Totik, The Corrosion Behavior of AISI 4140 Steel Subjected to Different Heat Treatments, Corrosion Reviews, 23 (2005) 4-5-6, 379-390, doi: 10.1515/CORRREV.2005.23.4-5-6.379
14 Y. Totik, The corrosion behaviour of manganese phosphate coatings applied to AISI 4140 steel subjected to different heat treatments, Surface & Coatings Technology, 200 (2006), 2711-2717, doi: 10.1016/j.surfcoat.2004.10.004
15 M.A. Hafeez, A. Farooq, Effect of Heat Treatments on the Mechanical and Electrochemical Corrosion Behavior of 38CrSi and AISI 4140 Steels, Metallography, Microstructure, and Analysis, 8 (2019) 479–487, doi: 10.1007/s13632-019-00556-x
16 Surface Morphology of Metal Electrodeposits. In: Fundamental Aspects of Electrometallurgy. Springer, Boston, MA, (2002), doi: 10.1007/0-306-47564-2_3
17 J. Wei, Y. Zhou, J. Dong, X. He, W. Ke, Effect of cementite spheroidization on improving corrosion resistance of pearlitic steel under simulated bottom plate environment of cargo oil tank, Materialia, Volume 6, (2019), 100316, doi: 10.1016/j.mtla.2019.100316
18 P.K. Katiyar, S. Misra, K. Mondal, Corrosion Behavior of Annealed Steel with Different Carbon Contents (0.002, 0.17, 0.43 and 0.7% C) in Freely Aerated 3.5% NaCl Solution, Journal of Materials Engineering and Performance, 28 (2019) 4041–4052, doi: 10.1007/s11665-019-04137-5