The Comparison Research of Plasma Surface Hardening of 34CrNiMo6 Steel Produced on Direct and Reversed Polarity Current

Abstract:

Many product parameters are basically determined by the state of the surface layer of the material from which it is produced. Increasing the hardness of the surface layer with unique core characteristics will significantly improve the performance characteristics of products and expand field of application of 34CrNiMo6 steel. The paper presents the results of a study of the surface plasma hardening of 34CrNiMo6 steel on direct and reversed polarity current. Studies of four possible variants of plasma surface quenching, including processing with scanning and processing in closed arc mode were carried out. The results of measuring geometric characteristics and hardness of the produced hardened layers are given. The possibility of producing hardened layers with a hardness up to 52 HRC is shown. The macro-and microstructure of the produced hardened layers using light microscopy was studied. The features of structure formation in layers hardened in different variants are analyzed. It is shown that it is possible to produce hardened layers with a depth of 1.7 mm and a width of up to 24 mm in the finishing plasma treatment without significant changes in the surface roughness.

• Periodical: Materials Science Forum (Volume 946)
• Pages: 906-912
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.946.906
• Online since: February 2019
• Authors: Dmitry S. Belinin*, Sergei D. Neylybin, Yuri D. Shitsyn
• Keywords: Chrome Nickel Molybdenum Steel, Microstructure, Plasma, Plasma Surface Hardening, Quenching Structures, Reverse Polarity of Current, Strengthening Technologies

References

[1] Yu.N. Tyurin, M.L. Zhadkevich, V.М. Mazunin, Strengthening of metal products using pulse-plasma technology, Welder in Russia. 1 (2007) 48-52.

[2] E.N. Safonov, V.I. Zhuravlev, Surface hardening of iron-carbon steels by hardening, Welding production, 10 (1997) 30-32.

[3] M.I. Goldstein, S.V. Grachev, Yu.G. Veksler, Special steels. Moscow: Metallurgy (1985).

[4] M.L. Bernshtein, A.G. Rakhshtadt (ed.), Metallurgy and heat treatment of steel. Directory. - 3rd ed., Pererab. and additional. - In 3 volumes. Mechanical Engineering, (1983).

[5] E.N. Safonov, New materials and technological processes to extend the life of rolling rolls. STI (f) USTU-UPI. Nizhny Tagil, (2005).

[6] L.K. Leshchinsky [and others], The influence of surface hardening technology with a highly concentrated heating source on the structure and fracture toughness of the weld metal and carbon steels, Welding production, 5 (1987) 3-5.

[7] L.K. Leshchinsky [and others], Plasma surface hardening, Technics, (1990).

[8] V.Yu. Shchitsyn, V.M. Yazovskikh, Yu.D. Shchitsyn, On thermal loads on the nozzle of a plasma torch when operating on a forward and reverse polarity, Sb. Theses of the Jubilee 20 th STC of welders of the Urals Welding of the Urals - 2001,, N. Tagil, (2001).

DOI: 10.1080/09507110209549563

[9] Yu.D. Shchitsyn, O.A. Kosolapov, N.N. Strukov, Energy distribution of the compressed arc during the operation of the plasma torch on the reverse polarity current, Welding and diagnostics, 3 (2010) 13-16.

[10] D.S. Belinin, Yu.D. Shchitsyn, P.S. Kuchev, N.N. Strukov, Technological variants of plasma hardening at the current of reverse polarity, Fundamental problems of technology and technology. 3-2 (2012) 99-104.