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Hydrogen behavior in the iron surface layer modified by plasma nitriding and ion boronising
Author(s) -
Lunarska E.,
Michalski J.
Publication year - 2000
Publication title -
materials and corrosion
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.487
H-Index - 55
eISSN - 1521-4176
pISSN - 0947-5117
DOI - 10.1002/1521-4176(200012)51:12<841::aid-maco841>3.0.co;2-f
Subject(s) - elastic recoil detection , hydrogen , nitriding , nitride , chemistry , metal , analytical chemistry (journal) , nuclear reaction analysis , surface layer , layer (electronics) , inorganic chemistry , materials science , metallurgy , chromatography , organic chemistry
The effects of the plasma nitriding with the formation of compound nitride and diffusion zones and of the boronising with the different ion doses on hydrogen distribution and hydrogen induced deterioration of a surface layer were examined in the case of Armco iron. Electrochemical studies of hydrogen permeation rate, hydrogen vacuum extraction measurements, optical and scanning microscopy, X‐ray diffraction and elastic recoil detection analysis (ERDA) were used. Accumulation of entering hydrogen within the various constitutent zones of the modified layer inhibits the hydrogen transport into the metal and thus, decreases the mean hydrogen content in the deeper zones and in the core. Hydrogen accumulation within the compact nitride zone causes the expansion of the nitride lattice, nitride phase transformation and deterioration. The ion boronising enhances the hydrogen effects in the plasma nitrided layers. Therefore, modification of the surface layer by plasma nitriding and ion boronising may result in preventing of the bulk metal from hydrogen induced degradation, but may cause hydrogen deterioration of the surface layer, depending on the treatment parameters.