COMPOSITION IN SURFACE OF LIQUID Fe-Mn AND Fe-S SYSTEMS

The effect of the surface active elements S and Mn on the surface tension of liquid Fe was investigated by the sessile drop method and their adsorptivity on the liquid Fe surface was calculated by the Gibb's equation. In order to compare the calculated with directly measured adsorption values, the distribution of S and Mn along different depth from the surface of liquid Fe-Mn and Fe-S binary system was analysed layer by layer by AES and/or glow discharge emission spectroscopy. Results indicated that a Mndepleted zone appeared along the depth of surface layer of alloy, and it is the same to S. The higher surface active element S is found to have a greater segregation coefficient about two orders of magnitude of that of Mn. This is analogous to the previous works on calculation of adsorption values from surface tension for the Fe-Mn and Fe-S binary systems.