Mechanisms of corrosion of structural materials in contact with coal chars in coal gasifier atmospheres. Semi-annual progress report
Five chromia-former alloys, Inconel 671, Hastelloy X, 310 stainless steel, Incoloy 800, and Haynes 188, have been exposed to both FMC char (2.7% S) and th Husky char (0.9% S) at 1600 and 1800/sup 0/F for 96 hours. Inconel 671 and 310 stainless corroded the most rapidly, Haynes 188 and Hastelloy had the best corrosion resistance, and Incoloy 800 was intermediate. Corrosion in the higher sulfur char (FMC) was generally more severe than that in the lower sulfur char (Husky), although the more corrosion-resistant alloys (Haynes 188 and Hastelloy X) showed minimal differences from one char to another. Hastelloy X showed an unusual effect of temperature, the corrosion rate being higher at 1600 than at 1800/sup 0/F in FMC char. The effect of preoxidation on FeCrAlY was to retard corrosion. However, an incubation period was observed, during wich sulfur penetrated the alumina film, followed by linear corrosion kinetics. The beneficial effect increased with increasing film thickness up to a critical value, beyond which corrosion was greater than for thinner films. It is believed that mechanical breakdown of the film caused this effect. A coating of 63Al-33Cr-4Hf on Incoloy 800 markedly retarded corrosion in FMC char at 1800/sup 0/F. Protection was attributed to the formation of Cr/sub 2/S/sub 3/ and Al/sub 2/S/sub 3/ in the reaction product. Corrosion in a mixture of H/sub 2/-10% H/sub 2/S at 950/sup 0/C (conditions giving a comparable sulfur activity as that in the FMC char at 1800/sup 0/F) was 6 times more rapid for Inconel 671 and over 3000 times more rapid for Hastelloy X. The scale structures were considerably different than those formed in char. 21 figures.
- Research Organization:
- California Univ., Los Angeles (USA). School of Engineering and Applied Science
- DOE Contract Number:
- AT03-76ET10692
- OSTI ID:
- 6227601
- Report Number(s):
- DOE/ET/10692-T4; ON: DE83009829
- Resource Relation:
- Other Information: Portions are illegible in microfiche products
- Country of Publication:
- United States
- Language:
- English
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The corrosion of some superalloys in contact with coal chars in coal gasifier atmospheres
Corrosion of some superalloys in contact with coal chars in coal gasifier atmospheres
Related Subjects
36 MATERIALS SCIENCE
CHARS
CORROSIVE EFFECTS
HASTELLOY X
CORROSION
HAYNES 188 ALLOY
HYDROGEN
HYDROGEN SULFIDES
INCOLOY 800
CORROSION RESISTANCE
PROTECTIVE COATINGS
INCONEL 671
STAINLESS STEEL-310
CHEMICAL REACTION KINETICS
COAL GASIFICATION
EXPERIMENTAL DATA
OXIDATION
RESEARCH PROGRAMS
SULFIDATION
VERY HIGH TEMPERATURE
ALLOYS
CHALCOGENIDES
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
HYDROGEN COMPOUNDS
INCOLOY ALLOYS
INFORMATION
IRON ALLOYS
IRON BASE ALLOYS
KINETICS
MATERIALS
MOLYBDENUM ALLOYS
NICKEL ALLOYS
NICKEL BASE ALLOYS
NONMETALS
NUMERICAL DATA
PYROLYSIS PRODUCTS
REACTION KINETICS
STAINLESS STEELS
STEELS
SULFIDES
SULFUR COMPOUNDS
THERMOCHEMICAL PROCESSES
TUNGSTEN ALLOYS
010404* - Coal
Lignite
& Peat- Gasification
360105 - Metals & Alloys- Corrosion & Erosion