Calculation of Physicochemical Conditions of the Formation of Protective Coatings Based on Carbides and Nitrides of Chromium

Authors N.A. Kharchenko1, A.I. Dehula1, V.G. Hignjak2 , Т.P. Hоvоrun1 , I.Y. Smokovych3

1Sumy State University, 2, Rymsky Korsakov St., 40007 Sumy, Ukraine

2National Technical University of Ukraine “I. Sikorsky Kyiv Polytechnic Institute”, 37, Peremohy Prosp., 03056 Kyiv, Ukraine

3Otto-von-Guericke University Magdeburg, 2 Universitätsplatz, 39106 Magdeburg, Germany

Issue Volume 12, Year 2020, Number 3
Dates Received 20 February 2020; revised manuscript received 15 June 2020; published online 25 June 2020
Citation N.A. Kharchenko, A.I. Dehula, V.G. Hignjak, et al., J. Nano- Electron. Phys. 12 No 3, 03038 (2020)
PACS Number(s) 61.46. – w, 62.20.Qp, 62.20. – х, 68.55.N
Keywords Thermodynamic calculations, Coatings (10) , Diffusion saturation, Condensed phase, Gas phase, Carbon steels.

Theoretical calculations of physical and chemical conditions of the process of diffusion saturation of carbon steels with nitrogen, carbon and chromium in the conditions of low pressure in the chlorine environment are carried out. The probable phase composition as a result of diffusion saturation is determined. The temperature interval for the existence of carbides and nitrides was established. The main probable condensed and gas phases that are formed as a result of saturation of carbon steels with carbon, nitrogen and chromium are identified. It is analyzed how the number of condensed and gas phases changes depending on the temperature of the diffusion coating process. It is theoretically established that two chromium nitrides CrN and Cr2N and chromium carbide Cr3C2 will be the main condensed phases as a result of deposition of the protective coating. The temperature interval for the existence of the main strengthening phases is established. Systems with oxygen content are analyzed. The formation of chromium oxides in the gas state is noted. It is determined that in the first and final stages of saturation (the initial and final temperatures of the saturation process), the main chromium-containing phase is chromium carbide and the almost complete absence of Cr2N nitride. The temperature of 1300 K is the optimum temperature at which a complex chromium carbide-nitride coating is formed. This combination of protective coating layers will have optimum properties in terms of wear and corrosion protection.

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