Kinetics and mechanism of high-temperature sulfidation of an Fe-23. 4Cr-18. 6Al alloy in H[sub 2]S-H[sub 2] atmospheres

Journal Article · Sat Aug 01 04:00:00 EDT 1992 · Oxidation of Metals; (United States)

DOI:https://doi.org/10.1007/BF00665042· OSTI ID:6999937

Przybylski, K ^[1]; Narita, T ^[2]; Smeltzer, W W ^[3]

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1. Academy of Mining and Metallurgy, Krakow (Poland)
2. Hokkaido Univ., Sapporo (Japan)
3. McMaster Univ., Hamilton, Ontario (Canada)

Sulfidation of an Fe-23.4Cr-18.6Al (at.%) alloy was investigated in H[sub 2]S-H[sub 2] atmospheres, 10[sup [minus]6] [le] P[sub s[sub 2]] [le] 10[sub 2] Pa, at 973 K. It was found over this pressure range that sulfidation after an early transient period followed the parabolic rate law, being diffusion controlled. An investigation was carried out of the scales formed during early transient sulfidation over the sulfur pressure range p[sub s[sub 2]] = 10[sup [minus]6]-10[sup [minus]2] Pa. Fully developed scales were multilayered consisting of an inner compact layer of equiazed grains, an intermediate layer of equiazed and columnar grains exhibiting a small degree of porosity, and an outer porous layer of distinct plates and needles. The grains of the inner and intermediate layers contained quaternary sulfide phases. The plates and needles were composed of hexagonal (FeCr)Al[sub 2]S[sub 4] and (CrAlFe)[sub 2]S[sub 3] from which pyrrhotite, FeS, grew at p[sub s[sub 2]] [ge] 10[sup [minus]4] Pa. The alloy exhibited a small degree of internal sulfidation; the precipitates were Al[sub 2]S[sub 3] doped with Cr and Fe. Marker measurements indicated that growth of the inner sulfide layer was supported by inward migration of sulfur. The morphological development of the scales at 973 K was similar to that obtained at 1,073 and 1,173 K.

• OSTI ID: 6999937
• Journal Information: Oxidation of Metals; (United States), Journal Name: Oxidation of Metals; (United States) Vol. 38:1-2; ISSN OXMEAF; ISSN 0030-770X
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010404 -- Coal
Lignite
& Peat-- Gasification
36 MATERIALS SCIENCE
360105* -- Metals & Alloys-- Corrosion & Erosion
ALLOYS
ALUMINIUM ALLOYS
ALUMINIUM COMPOUNDS
ALUMINIUM SULFIDES
CHALCOGENIDES
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CHROMIUM ALLOYS
COAL GASIFICATION
CORROSION PRODUCTS
DATA
DIFFUSION
ELECTRON MICROSCOPY
ELEMENTS
EXPERIMENTAL DATA
GASIFICATION
HYDROGEN
HYDROGEN COMPOUNDS
HYDROGEN SULFIDES
INFORMATION
IRON ALLOYS
IRON BASE ALLOYS
KINETICS
LAYERS
MICROSCOPY
MORPHOLOGY
NONMETALS
NUMERICAL DATA
PARTIAL PRESSURE
PHASE STUDIES
POROSITY
REACTION KINETICS
SCALING
SCANNING ELECTRON MICROSCOPY
SULFIDATION
SULFIDES
SULFUR COMPOUNDS
TEMPERATURE RANGE
TEMPERATURE RANGE 0400-1000 K
THERMOCHEMICAL PROCESSES