Corrosion behavior of SiC under simulated slagging gasifier conditions

Journal Article · Tue Oct 01 04:00:00 EDT 1985 · Mater. Compon. Fossil Energy Appl.; (United States)

OSTI ID:6508003

Easler, T E; Poeppel, R B

Ceramic materials under scrutiny as candidates for structural components in severe environments include silicon carbide, silicon nitride, and alumina-based (corundum, mullite, spinel) materials. Interest is maintained in these materials because of their low densities, high strengths, retained strength at high temperatures, thermal shock resistance, and resistance to oxidation and corrosive attack. Although some work has been reported on the effects of oxidation and exposure to oxidizing combustion environments on the behavior of ceramic materials, many questions remain - in particular, concerning their behavior in the low-oxygen partial pressure (reducing) environments encountered in coal gasification. The anticipated active oxidation behavior in a low oxygen potential, non-slagging environment was not observed for the two silicon carbide materials under simulated slagging gasifier conditions. The oxidation reaction apparently was influence by the relatively high steam partial pressure. Specimens coated with acidic or basic slag compositions prior to exposure exhibited significant weight losses that were more substantial in the case of the basic slag-coated specimens. The viscosity of the fused slag at the reaction temperature is believed to have significant influence over the extent of reaction. Formation of a protective oxide scale is prevented, and reduction of iron oxide in the slag to metallic iron was followed by penetration of iron into subsurface pores in the underlying silicon carbide, forming iron-rich pockets.

• Research Organization: Argonne National Lab., IL
• OSTI ID: 6508003
• Journal Information: Mater. Compon. Fossil Energy Appl.; (United States), Journal Name: Mater. Compon. Fossil Energy Appl.; (United States) Vol. 58; ISSN MCFAD
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010404* -- Coal
Lignite
& Peat-- Gasification
36 MATERIALS SCIENCE
360205 -- Ceramics
Cermets
& Refractories-- Corrosion & Erosion
CARBIDES
CARBON COMPOUNDS
CHEMICAL REACTIONS
COAL GASIFICATION PLANTS
CORROSION
INDUSTRIAL PLANTS
MATERIALS
OXIDATION
SILICON CARBIDES
SILICON COMPOUNDS
SLAGS
WEIGHT