Degradation of Fe-25Cr, Fe-25Cr-20Ni and Fe-25Cr-6A1 alloys in H/sub 2//H/sub 2/O/H/sub 2/S environments at 700/degree/C

Technical Report · Wed Mar 01 00:00:00 EST 1989

DOI:https://doi.org/10.2172/6194380· OSTI ID:6194380

Vedula, K.

Fe-25wt%Cr, Fe-25wt%Cr-20wt%Ni and Fe-25wt%Cr-6wt%Al alloys have been exposed to H/sub 2//H/sub 2/O/H/sub 2/S/Ar gas mixtures at 700/degree/C. The mechanisms of formation and degradation of oxide scales on these alloys have been investigated using electron microscopy and surface analytical techniques. The Fe-25Cr-6Al alloy is attacked the least as a result of the formation of a Al/sub 2/O/sub 3/ layer in the scale, whereas the Fe-25Cr-20Ni alloy is attacked the most, through rapid formation of Fe and Ni sulfides. The Fe-25Cr alloy, forms a Cr/sub 2/O/sub 3/ scale containing CrS/sub 1. 17/ precipitates, and other phases which eventually lead to scale breakdown. 17 refs., 8 figs., 3 tabs.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 6194380
• Report Number(s): ORNL/Sub-86-95900/01; ON: DE89011873
• Resource Relation: Other Information: Paper copy only, copy does not permit microfiche production
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
01 COAL, LIGNITE, AND PEAT
ALUMINIUM ALLOYS
CORROSION
CHROMIUM ALLOYS
HYDROGEN
CORROSIVE EFFECTS
HYDROGEN SULFIDES
IRON BASE ALLOYS
NICKEL ALLOYS
ARGON
CHROMIUM OXIDES
COMPARATIVE EVALUATIONS
IRON SULFIDES
MICROSTRUCTURE
SCALING
ALLOYS
CHALCOGENIDES
CHEMICAL REACTIONS
CHROMIUM COMPOUNDS
CRYSTAL STRUCTURE
ELEMENTS
FLUIDS
GASES
HYDROGEN COMPOUNDS
IRON ALLOYS
IRON COMPOUNDS
NONMETALS
OXIDES
OXYGEN COMPOUNDS
RARE GASES
SULFIDES
SULFUR COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
360105* - Metals & Alloys- Corrosion & Erosion
010404 - Coal
Lignite
& Peat- Gasification
010405 - Coal
Lignite
& Peat- Hydrogenation & Liquefaction
014000 - Coal
Lignite
& Peat- Combustion