Abstract
Surface segregation in an Fe-20 mass%Cr single crystal alloy was investigated by using Auger electron spectroscopy with in situ heating. Segregation of chromium to the free surface took place by heating above about 750 K. The experiment of the segregation kinetics showed that the segregation process was controlled by diffusion of chromium in the alloy. In spite of the low concentration of residual nitrogen in the alloy, remarkable surface segregation of nitrogen was also observed. It was shown that the segregation of nitrogen was strictly correlated with that of chromium through the segregation process. It may result from an attractive interaction between chromium and nitrogen in the segregated layer on the surface. A model for the segregation behavior was proposed, and the effect of the interaction between solutes on the interface segregation was discussed with previous results.
