Sulfidation-resistant alloy for coal gasification service. Quarterly report, September 1--November 30, 1977. [Fe--18Cr--5Al--1Mo--1Hf]

Technical Report · Mon Dec 12 00:00:00 EST 1977

DOI:https://doi.org/10.2172/6762215· OSTI ID:6762215

Perkins, R. A.; Bhat, M. S.

An Fe-18Cr-5Al-1Mo-1Hf alloy has been tested in synthetic coal gasification atmospheres at 500 and 1000 psi pressure. Resistance to attack is similar to that observed at atmospheric pressure. Tests also have been made at high pressure in a low P/sub O/sub 2//-high P/sub S/sub 2// atmosphere representative of low Btu gasification. The alloy did not resist attack under these conditions and has a transition to non-protective behavior with decreasing P/sub O/sub 2// and/or increasing P/sub S/sub 2//. A molybdenum alloy (TZM-Mo) is being screened for sulfidation resistance in coal gasification atmospheres. Initial tests at 1800/sup 0/F in the DOE/MPC gas mixture show a parabolic rate behavior with negligible attack. Extrapolation of the data indicates a potential loss of 0.2 mil in one year, with 1% H/sub 2/S in the gas. Samples will be exposed to a cumulative time of 4000 hr to obtain more accurate rate data. Impact tests indicate that Al and Si lower the notched impact toughness and raise the ductile to brittle transition temperature of Fe-Cr alloys with 17-19Cr. The addition of 1 to 2% Mo slightly improves impact behavior. An Fe-18Cr-5Al-1Mo-1Hf alloy is concluded to have the best combination of corrosion resistance and mechanical properties. This composition and an upper limit composition of 19Cr-6Al-2Mo-1Hf have been selected for the final Phase III evaluation. Two 50-lb ingots of each composition have been vacuum induction melted and cast successfully.

• Research Organization: Lockheed Palo Alto Research Labs., Calif. (USA); California Univ., Berkeley (USA). Dept. of Materials Science and Engineering
• DOE Contract Number: EX-76-C-01-2299
• OSTI ID: 6762215
• Report Number(s): FE-2299-18; TRN: 78-013563
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
01 COAL, LIGNITE, AND PEAT
ALLOY-TZM
CORROSION RESISTANCE
MECHANICAL PROPERTIES
ALUMINIUM ALLOYS
CHROMIUM ALLOYS
COAL GASIFICATION PLANTS
CORROSION PROTECTION
HAFNIUM ALLOYS
HYDROGEN SULFIDES
CORROSIVE EFFECTS
IRON BASE ALLOYS
MOLYBDENUM ALLOYS
SULFUR
CORROSION
MATERIALS TESTING
MEDIUM PRESSURE
SILICON ALLOYS
VERY HIGH TEMPERATURE
ALLOYS
CHALCOGENIDES
CHEMICAL REACTIONS
ELEMENTS
HYDROGEN COMPOUNDS
INDUSTRIAL PLANTS
IRON ALLOYS
MOLYBDENUM BASE ALLOYS
NONMETALS
SULFIDES
SULFUR COMPOUNDS
TESTING
TITANIUM ALLOYS
ZIRCONIUM ALLOYS
360105* - Metals & Alloys- Corrosion & Erosion
010404 - Coal
Lignite
& Peat- Gasification