Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7807329 | Journal of Molecular Structure | 2018 | 8 Pages |
Abstract
The paper presents a structure of a nitrided layer formed with active screen plasma nitriding (ASPN) technique, which is a modification of plasma nitriding. The model investigated material was Fe Armco. The nitriding processes were carried out at 773 K for 6 h and 150 Pa. The main objective of this study was to confirm nitrogen migration effect and its influence on the nitride layer formation in different area of the layer interfaces (ε/ε+γâ²/γâ²). The results of the tests were evaluated using scanning electron microscopy (SEM, SEM/EBSD), transmission electron microscopy - electron energy loss spectroscopy (TEM-EFTEM), secondary ion mass spectroscopy (SIMS) and Wavelength Dispersive X-Ray Spectrometry (WDS). The analysis of the results suggests that the structures of the nitrided layers and nitrides morphology differ for various parameters and are dependent on the surface layer saturation mechanism for each of the temperatures and process parameters. New approaches in diffusion of nitrogen and carbon atoms and optimizing process were also analyzed. Nitrogen and also carbon transport in the sublayer was observed by several effects i.e. uphill diffusion effect which confirmed migration of the atoms in diffusive layer towards top surface (ε/ε+γⲠinterface) and stress change effect in the nitrogen saturation area of the (Fe(C,N)+γâ²) layer. Results showed in the paper might be used both for optimization of ASPN processes, modeling of nitrided layers formation mechanism and for controlling the nitrided layers morphology when nitriding different Fe based materials.
Related Topics
Physical Sciences and Engineering
Chemistry
Organic Chemistry
Authors
J.J. Jasinski, T. Fraczek, L. Kurpaska, M. Lubas, M. Sitarz,