ISSN:
1573-4889
Keywords:
sulfidation
;
Fe-Mn-Mo
;
FexMo6S8−z
;
three-layered scale
;
internal sulfidation
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract Iron-base alloys containing ca. 27 a/o (atomic percent) manganese and up to 17.3 a/o molybdenum were sulfidized in H2/H2S gases of 4 Pa sulfur partial pressure at temperatures of 700–1000° C. Three-layered scales developed on all the molybdenum-containing alloys, and an internal sulfidation zone was observed in most cases. The overall scaling process and individual layer growth all followed parabolic kinetics. The outer and intermediate layers comprised Fe(Mn)S and Mn(Fe)S, respectively. Sulfidation rates varied with the morphology and constitution of the inner layer. The reaction product FexMo6S8−z, which was restricted to the inner layer, is permeable to sulfur, iron and manganese, but not molybdenum.For high-molybdenum levels, the overall scaling rate decreased, as a result of the slow diffusion of iron in FexMo6S8−z. For low-molybdenum levels, this beneficial effect is small and outweighed by the formation of an inner two-phase layer.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00664493
