Obrabotka Metallov. 2016 no. 3(72)

ОБРАБОТКА МЕТАЛЛОВ № 3 (72) 2016 49 МАТЕРИАЛОВЕДЕНИЕ Abstract Purpose: To improve the operational properties of machine parts, the methods of modifying the surface layers of parts with highly concentrated energy sources, providing a heating rate of about 10 4 ... 10 5 o C/sec, are becoming more common. The target of the research is high-energy heat hardening of the surface by high-frequency currents (HEH HFC). This energy source is characterized by highly complicated energy distribution in the depth of the heated layer, which may cause the formation of micro volumes of molten metal in the depth of the material, leading to a significant reduction in the quality of the workpiece. Consequently, when setting the process parameters, it is necessary to take into account the processing characteristics by the given heat sources. Methods: Full-scale experiments are carried out on the cylindrical grinding machines 3B12, having an additional source of energy in the form of the external quenching circuit implementing high-energy heating by high-frequency currents. Structural studies are carried out using optical and scanning electron microscopy. Mathematical modeling of thermal fields and structural phase transitions using HEH HFC is carried out in ANSYS and SYSWELD software systems. Results and Discussion: It is theoretically grounded and proven in use that when performing the surface hardening of steel 45 using the high- energy heating by high-frequency currents and simultaneous shower water-cooling, the liquid phase may occur not on the surface but at the depth of 0,15...0,2 mm. Basing on the research the conclusion is as follows: when setting the processing parameters of the HEH HFC surface hardening with simultaneous shower water-cooling, they must be based on the most heat-stressed layer. Keywords surface hardening, high-frequency currents, FEM, structural steel, the liquid phase. DOI: 10.17212/1994-6309-2016-3-41-51 References 1. Abashkin V.V., Gorshkov O.A., Ilyin A.A., Lovtsov A.S., Rizakhanov R.N. Multipass surface hardening of steel samples with inclined surfaces by concentrated electron beam in the air of atmosphere pressure. High Tem- perature Material Processes: an International Quarterly of High-Technology Plasma Processes , 2004, vol. 8, iss. 3, pp. 427–432. doi: 10.1615/HighTempMatProc.v8.i3.80 2. Davis J.R. Surface hardening of steels: understanding the basics. Materials Park, Ohio, ASM International Publ., 2002. 364 p. ISBN 978-0-87170-764-2 3. Skeeba V.Yu., Pushnin V.N., Erokhin I.A., Kornev D.Yu. Analiz napryazhenno-deformirovannogo sostoyaniya materiala pri vysokoenergeticheskom nagreve tokami vysokoi chastoty [Analysis of the stress-strain state of the material under high-energy heating by high frequency currents]. Obrabotka metallov (tekhnologiya, oborudovanie, instrumenty) – Metal Working and Material Science , 2014, no. 3 (64), pp. 90–102. 4. Béjar M.A., Henríquez R. Surface hardening of steel by plasma-electrolysis boronizing. Materials and Design , 2009, vol. 30, iss. 5, pp. 1726–1728. doi: 10.1016/j.matdes.2008.07.006 5. Skeeba V.Yu., Ivancivsky V.V., Kutyshkin A.V., Parts K.A. Hybrid processing: the impact of mechanical and surface thermal treatment integration onto the machine parts quality. IOP Conference Series: Materials Science and Engineering , 2016, vol. 126, p. 012016. doi: 10.1088/1757-899X/126/1/012016 6. Skeeba V., Pushnin V., Kornev D. Quality improvement of wear-resistant coatings in plasma spraying in- tegrated with high-energy heating by high frequency currents. Applied Mechanics and Materials , 2015, vol. 788, pp. 88–94. doi: 10.4028/www.scientific.net/AMM.788.88 7. Plotnikova N., Losinskaya A., Skeeba V., Nikitenko E. Perspective of high energy heating implementation for steel surface saturation with carbon. Applied Mechanics and Materials , 2015, vol. 698, pp. 351–354. doi: 10.4028/ www.scientific.net/AMM.698.351 8. Bataev I.A., Golkovskii M.G., Bataev A.A., Losinskaya A.A., Popelyukh A.I., Drobyaz E.A. Surface hard- ening of steels with carbon by non-vacuum electron-beam processing. Surface and Coatings Technology , 2014, vol. 242, pp. 164–169. doi: 10.1016/j.surfcoat.2014.01.038 9. Vodopyanov E.M., Loginova A.V., Ivashutenko A.S., Martyushev N.V. Oxide powder plasma processing by low-energy ions of titanium. Applied Mechanics and Materials , 2015, vol. 756, pp. 299–302. doi: 10.4028/www. scientific.net/AMM.756.299 10. Akarachkin S.V., Sivkov A.A., Ivashutenko A.S., Martyushev N.V. Physical-mechanical properties of co- rundum-zirconium ceramic obtained by the technology of radial magnetoimpulse pressing. Applied Mechanics and Materials , 2015, vol. 756, pp. 286–292. doi: 10.4028/www.scientific.net/AMM.756.286