Thermogravimetric measurements in H2/H2S environments for up to five hours were carried out to determine the sulphidizing behavior of Fe-20Cr and Fe-20Cr-0.7Y alloys. These measurements helped to determine the mechanism of sulphidization in the early stages. The reaction products were characterized using a scanning electron microscope coupled to an energy dispersive analyzer and by X-ray diffraction analysis. The addition of yttrium influenced the morphology of the sulphide layer and the reaction kinetics.
sulphidation; reactive elements
