Effect of preoxidation on the corrosion of some alloys in coal chars and sulfur vapor. Final report
Preoxidation of several chromia-former and of several alumina-former alloys at temperatures ranging from 1800 to 2300/sup 0/F in either water-saturated argon or in air was performed prior to corrosion in coal char or in sulfur vapor. Chromia films offered no protection to sulfidation in both char and sulfur vapor environments. The chromia films were adherent but permitted rapid inward penetration of sulfur and outward penetration of cations to form extensive sulfides. Alumina films offered protection for much longer times than chromia films but localized cracking and/or spalling of the alumina permitted rapid attack at the exposed areas. The addition of yttrium as either a metallic element or as an oxide dispersion improved the mechanical stability of the films and prolonged the period of protectiveness. A binary alloy, Fe-13Al, sulfidized more raidly after preoxidation than before preoxidation. Alumina films would provide an excellent protective barrier if thick, crack-free films could be grown at reasonable temperatures. The low growth rates at very high temperatures and the susceptibility of alumina films to crack and spall during thermal cycling suggest that preoxidation will not offer adequate corrosion resistance for alloys exposed to char in goal gasifiers.
- Research Organization:
- California Univ., Los Angeles (USA). School of Engineering and Applied Science
- DOE Contract Number:
- AT03-76ET10698
- OSTI ID:
- 5156690
- Report Number(s):
- DOE/ET/10698-T1
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
36 MATERIALS SCIENCE
ALLOYS
CORROSION RESISTANCE
MATERIALS TESTING
PROTECTIVE COATINGS
CHARS
CORROSIVE EFFECTS
HASTELLOY X
SULFIDATION
HAYNES 188 ALLOY
INCOLOY 800
STAINLESS STEEL-310
SULFUR
ALUMINIUM
CHROMIUM
COAL GASIFICATION
EXPERIMENTAL DATA
YTTRIUM
CHEMICAL REACTIONS
CHROMIUM ALLOYS
CHROMIUM STEELS
CHROMIUM-NICKEL STEELS
COATINGS
COBALT ALLOYS
CORROSION RESISTANT ALLOYS
DATA
ELEMENTS
GASIFICATION
HASTELLOYS
HEAT RESISTANT MATERIALS
HEAT RESISTING ALLOYS
INCOLOY ALLOYS
INFORMATION
IRON ALLOYS
IRON BASE ALLOYS
MATERIALS
METALS
MOLYBDENUM ALLOYS
NICKEL ALLOYS
NICKEL BASE ALLOYS
NONMETALS
NUMERICAL DATA
PYROLYSIS PRODUCTS
STAINLESS STEELS
STEELS
TESTING
THERMOCHEMICAL PROCESSES
TRANSITION ELEMENTS
TUNGSTEN ALLOYS
010404* - Coal
Lignite
& Peat- Gasification
360105 - Metals & Alloys- Corrosion & Erosion