Distribution around the oxide-substrate interface of alloying elements in low-carbon steel

In order to study the physicochemical evolution during oxidation of Fe-C-Si gma X-i alloys surfaces (X-i = Cu, Ni, Al, Si, S, with X-i% < 0.5 wt. %, C% < 0.1 wt. %), an original analysis method has been used. After separating the oxide from the metal substrate, the first atomic layers of both inner s urfaces have been observed by Auger Electron Spectroscopy (AES). The depth profiles obtained, around 0.4 mu m thick oil both sides of the oxide-metal interface, have been compared for four steels of different composition. Sig nificant differences have been observed and described in this paper. A qual itative interpretation of diffusion processes has been proposed. A metallog raphic study illustrates some physical consequences of alloying elements, e specially on the scale thickness.