1996 Volume 36 Issue 10 Pages 1273-1278
Angle-resolved X-ray photoelectron spectroscopy (AR-XPS) has been used for characterizing thin oxide layers formed on the surface of 17Cr-Ni-Mo-N austenitic steels. It was confimed that chromium and nitrogen segregation takes place on the surface by in-situ heating at 973 K under ultra high vacuum. The effective thickness and concentration of their segregated layer was estimated from the relationship between the concentration and the take-off angle in AR-XPS. AR-XPS study was also made for specimens without and with segregated surface layers which were subsequently exposed to air at room temperature. The surface segregation of chromium and nitrogen was found to considerably inhibit oxidation at room temperature, and such feature was rather distinct compared with the ferritic steel case by chromium segragation alone. These results on the surface layers were consistent with changes in the observed chemical state denoted by Fe 2p and Cr 2p due to the surface segregation.