Physical and Technological Parameters of Cr28 Steel Nitriding in an Ammonia Environment

Authors T.V. Loskutova1 , I.S. Pohrebova1 , S.M. Kotlyar1, M.M. Bobina1, D.A. Kaplii1, N.A. Kharchenko2 , T.P. Hоvоrun2

1National Technical University of Ukraine “I. Sikorsky Kyiv Polytechnic Institute”, 37, Prosp. Peremohy, 03056 Kyiv, Ukraine

2Sumy State University, 2, Rimsky Korsakov Str., 40007 Sumy, Ukraine

Issue Volume 15, Year 2023, Number 1
Dates Received 03 January 2023; revised manuscript received 15 February 2023; published online 24 February 2023
Citation T.V. Loskutova, I.S. Pohrebova, et al., J. Nano- Electron. Phys. 15 No 1, 01013 (2023)
PACS Number(s) 61.46. – w, 62.20.Qp, 62.20. – х, 68.55N
Keywords Nitrided coatings, Microhardness (2) , Wear resistance (2) .

The paper examines the effect of technological parameters of gas nitriding (temperature and time) on the phase composition, structure, microhardness, and wear resistance of the Cr28 ferritic class corrosion-resistant steel. Nitriding was carried out in an environment of dissociated ammonia in the temperature range of 550-950 ºС. The dependence of the phase composition of the formed coatings on the nitriding temperature was established. X-ray structural, metallographic, and durometric analyses determined that the following phases are formed due to nitriding: Fe2N, Fe4N, Feα, Feγ, and CrN. The maximum microhardness of 15.5-16.0 GPa was recorded for coatings on Cr28 steel after nitriding at a temperature of 550 ºС. The influence of the annealing temperature on the microhardness of the nitrided coating was analyzed. A decrease in the microhardness of the nitrided coating on Cr28 steel starting from the annealing temperature of 600 ºC was recorded. It was established that the minimum reduction in microhardness at an annealing temperature of 750 ºС is characteristic of Cr28 steel nitrided at a temperature of 550 ºС. The optimal mode of nitriding (temperature 550 ºC, time 6 hours) was determined, which allows for obtaining the maximum abrasive resistance of Cr28 steel after nitriding. At the same time, a 2.8-fold increase in the wear resistance of nitrided Cr28 steel compared to the original structure is recorded.

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