EVOLUTION OF SULFIDE SCALES ON Fe-Mo ALLOYS DURING SULFIDATION
(Open Laboratory for Corrosion and Erosion; Department of Surface Science and Corrosion Engineering; University of Science and Technology Beijing; Beijing 100083)
Abstract: A summary was given to the development of the sulfide scales on several Fe- Mo alloys sulfidized in S2 vapor at high temperatures. The influences of alloy composition and microstructure, formation and growth of the relevant sulfides on the evolution of the scale structure were discussed. The scale structure on Fe-Mo alloy depends strongly on alloy composition. High amount of Mo in alloy could promote the development of MoS 2 layer, which serves as the main product to resist sulfidation. The addition of Mo in alloy up to 57% can not either eliminate the external FeS layer or resist its thickening. However, the MoS2 layer caused by the increase of Mo in alloy can stimulate the occurrence of FeMo6S8 layer by blocking Fe outwards diffusion.
Key words: Fe Mo alloy sulfidation microstructure