Observation of ion nitriding on FeCr, FeNi and NiCr alloy surfaces in a glow discharge plasma

For FeCr, FeNi and NiCr alloys, iron nitriding in a glow discharge plasma was investigated by optical emission spectroscopy and Auger electron spectroscopy. The composition change in depth was provided by both techniques and, in addition, Auger nitrogen‐metal interatomic transitions give information about chemical environments surrounding N atoms. Chromium‐enrichment in the nitrided layers was observed from the variation both in the nitrogen‐KLL Auger lineshapes and in the depth profiles. The chemical composition in the layers was strongly affected by the alloyed chromium having a strong affinity with N in the chromium‐containing alloys.