2_2021_sen_6

Title of the article INFLUENCE OF PRE-OXIDATION ON THE NITRIDING PROCESS OF IRON ALLOYS
Authors

GAHRAMANOV Vurgun F., Ph. D. in Eng., Senior Lecturer of the Department “Metallurgy and Metallurgical Science”, Azerbaijan Technical University, Baku, Republic of Azerbaijan, This email address is being protected from spambots. You need JavaScript enabled to view it.">This email address is being protected from spambots. You need JavaScript enabled to view it.

ASLANOV Elbey A., Ph. D. in Phys. and Math., Associate Professor of the Department “Mechanics”, Azerbaijan Technical University, Baku, Republic of Azerbaijan, This email address is being protected from spambots. You need JavaScript enabled to view it.">This email address is being protected from spambots. You need JavaScript enabled to view it.
In the section MECHANICAL ENGINEERING MATERIALS AND TECHNOLOGIES
Year 2021
Issue 2
Pages 54–59
Type of article RAR
Index UDK 621.762
DOI https://doi.org/10.46864/1995-0470-2021-2-55-54-59
Abstract The article presents the results of studying the kinetics of oxidation of Fe-Cr, Fe-Al and iron alloys at temperatures of 450–550 °C. The influence of preliminary oxidation of these alloys on the nitriding process has been studied. It has been established that alloying of Fe-Cr, Fe-Al alloys increases the amount of absorbed nitrogen, but decreases the overall depth of the nitrided layer. The duration of nitriding required to develop high hardness (over HV 1,000) depends on the composition of the solid solution. At a nitriding temperature of 520 °C, exposure is 10–15 minutes for steels of the first group, at least 3–4 h for steels of the second and third groups, and 5–6 h for steels of the fourth group. Studies have shown that the hardness of the layer is determined mainly by the composition of the solid solution; the amount and dispersion of the carbide phase have less effect. The hardness increases as a result of an increase in the hardening temperature and a decrease in the tempering temperature, which reduce the amount of the carbide phase, but increase the alloying of the solid solution. The hardness of the nitrided layer of high-speed steels P9, P18, having the same composition of the solid solution, is the same (HV 1,340) even despite the significant difference in the amount of the carbide phase. The hardness of the layer of steel 4Х5В2ФС (4Kh5V2FS), which contains more chromium in the solution, is HV 50–90 higher than the hardness of the layer on the steel 3Х2В8Ф (3Kh2V8F), which has 1.5–2 times more of the carbide phase. The behavior of steels with the same high chromium content (12 %), but different carbon content is characteristic. The hardness of the layer in steel 1Х13 (1Kh13), which has few carbides, is HV 100–180 higher than the hardness of the layer in steel Х12М (Kh12M), in which a significant portion of chromium is bound into carbides.
Keywords composition, modes, nitriding, iron and alloys, diffusion, steel, ammonia
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Bibliography
  1. Namazov S.N., Gahramanov B.F. Izuchenie vliyaniya azotirovaniya na svoystva soedineniy na osnove zheleza [Study of the effect of nitriding on the properties of iron-based compounds]. Sənaye ilinə həsr olunmuş elmi-texniki konfrans [Scientific and technical conference dedicated to the Year of Industry]. Baku, 2014, pp. 61–65 (in Russ.).
  2. Widi K.A., Sujana W., Rahardjo T. Surface microporous formation on AISI 4140 using combination of diffusion treatment after nitriding gas in muffle reactor. International journal of surface science and engineering, 2020, vol. 14, iss. 4, pp. 320–335.
  3. Pye D. Nitriding techniques, ferritic nitrocarburizing, and austenitic nitrocarburizing techniques and methods. Steel heat treatment: Metallurgy and technologies, 2006, pp. 475–538.
  4. Dvortsin M.D., Yakhnina V.D. The stainless steel nitriding problem. Chemical and petroleum engineering, 1966, vol. 2, no. 2, pp. 95–100.
  5. Smirnov A.V., et al. Azotirovanie passiviruyushchikhsya staley s primeneniem chetyrekhkhloristogo ugleroda [Nitriding of passivating steels using carbon tetrachloride]. Leningrad, 1964. 23 p. (in Russ.).
  6. Dudan A.V., Rutkovsky A.V., Ahieiev M.S., Mirnenko V.I., Smyrnovа Т.V., Radko O.V. Povyshenie prochnostnykh svoystv poverkhnostey stalnykh detaley vakuumnym termotsiklicheskim azotirovaniem v plazme pulsiruyushchego tleyushchego razryada [Increasing the strength properties of surfaces of steel parts vacuum thermocyclic nitrogenization in plasma of pulsating great discharge]. Herald of Polotsk State University. Series B, Industry. Applied sciences, 2020, no. 11, pp. 45–54 (in Russ.).
  7. Pogrebetskaya T.M., Onokhin V.F. Nitriding of engine cylinders with the use of carbon tetrachloride. Metal science and heat treatment, 1969, vol. 11, no. 8, pp. 646–648.
  8. Namazov S.N., Gahramanov V.F. Uluchshenie mekhanicheskikh svoystv poroshkovykh kompozitsionnykh materialov na osnove zheleza posle tsementatsii i borirovaniya [Improvement of mechanical properties of iron-based powder composite materials after carburizing and boronizing]. Bulletin of the National Technical University “KhPI”. Series: Automobile and tractor construction, 2018, no. 49(1325), pp. 63–66 (in Russ.).
  9. Davies M.H., Simnad M.T., Birchenall C.E. On the mechanism and kinetics of the scaling of ıron. Journal of metals, 1951, vol. 3, no. 10, pp. 889–896.
  10. Gorbunov N.S. Diffuzionnye pokrytiya na zheleze i stali [Diffusion coatings on iron and steel]. Moscow, Akademiya nauk SSSR Publ., 1958. 207 p. (in Russ.).
  11. Prescott R., Graham M.J. The oxidation of iron-aluminum alloys. Oxidation of metals, 1992, vol. 38, no. 1, pp. 73–87.
  12. Dubinin G.N. Diffuzionnoe khromirovanie splavov [Diffusion chrome plating of alloys]. Moscow, Mashinostroenie Publ., 1964. 450 p. (in Russ.).
  13. Popov A.A. Teoreticheskie osnovy khimiko-termicheskoy obrabotki stali [Theoretical foundations of chemical and thermal treatment of steel]. Moscow, Metallurgiya Publ., 1962. 120 p. (in Russ.).
  14. Namazov S.N., Gahramanov V.F. Tekhnologicheskie osobennosti khimiko-termicheskoy obrabotki vypechennykh testovykh kompozitsiy [Technological features of chemical and heat treatment of baked test compositions]. Nauchnye trudy AzTU. Spetsvypusk, 2013, pp. 75–77.
  15. Nechaev V.V., et al. Fizicheskoe materialovedenie. Tom 2. Osnovy materialovedeniya [Material physics. Volume 2. Fundamentals of materials science]. Moscow, Moskovskiy inzhenerno-fizicheskiy institut (gosudarstvennyy universitet) Publ., 2007. 606 p. (in Russ.).
  16. Kubaschewski O., Hopkins B.E. Oxidation of metals and alloys. Butterworths, 1962. 319 p.
  17. Lakhtin Yu.M. Fizicheskie osnovy protsessa azotirovaniya [Physical fundamentals of the nitriding process]. Moscow, Mashgiz Publ., 1948. 144 p. (in Russ.).