The Effects of Modifying the Activity of Nitriding Media by Diluting Ammonia with Nitrogen.

Autor: Cojocaru MO; Department of Metallic Materials Science, Physical Metallurgy, Faculty of Materials Science and Engineering, University POLITEHNICA of Bucharest, 060042 Bucharest, Romania.; Section IX-Materials Science and Engineering, Technical Sciences Academy of Romania, 030167 Bucharest, Romania., Branzei M; Department of Metallic Materials Science, Physical Metallurgy, Faculty of Materials Science and Engineering, University POLITEHNICA of Bucharest, 060042 Bucharest, Romania., Ghinea AM; Department of Metallic Materials Science, Physical Metallurgy, Faculty of Materials Science and Engineering, University POLITEHNICA of Bucharest, 060042 Bucharest, Romania., Druga LN; Section IX-Materials Science and Engineering, Technical Sciences Academy of Romania, 030167 Bucharest, Romania.; Research Department, UTTIS Industries SRL, 077185 Vidra, Romania.
Jazyk: angličtina
Zdroj: Materials (Basel, Switzerland) [Materials (Basel)] 2021 May 07; Vol. 14 (9). Date of Electronic Publication: 2021 May 07.
DOI: 10.3390/ma14092432
Abstrakt: This paper discusses the issue of the effects of modifying the activity of nitriding media by diluting ammonia with nitrogen and the concomitant variation in the degree of ammonia dissociation on the layer's growth kinetics and their phase composition. To understand and quantify the effects of the variation in the main parameters that influence the layer growth kinetics, the experimental programming method was used and mathematical models of interactions between influence and kinetics parameters were obtained for two metallic materials: Fe-ARMCO and 34CrAlMo5 nitralloy steel. It was concluded that the nitriding operating temperature and the degree of nitrogen dilution of the ammonia have statistically significant influences on the kinetics of the nitrided layer. In the same context, it was analytically proved and experimentally confirmed that the ammonia degree dissociation from the gaseous ammonia-nitrogen mixture, along with the dilution degree of the medium with nitrogen, significantly influences the nitrogen potential of the gaseous mixture used for nitriding and thus the concentration of nitrogen in balance at the medium thermochemically processed metal product interface.
Databáze: MEDLINE
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