Hot corrosivity of coal gasification products on gas turbine alloys. Summary report, 15 April 1978-15 November 1979

Technical Report · Mon Jan 01 04:00:00 EST 1979

DOI:https://doi.org/10.2172/5253538· OSTI ID:5253538

Meier, G H; Gulbransen, E A

The results of this investigation have produced mechanisms for the hot corrosion of a number of pure metals and alloys in the types of atmospheres likely to be obtained in turbines using coal conversion products as fuel. The results of these mechanistic studies suggest the following conclusions regarding application of alloys in these situations: (1) Simple Cr/sub 2/O/sub 3/-forming alloys of both Co and Ni have good hot corrosion resistance to most of the deposits likely to form in turbines burning coal conversion products with the exception of deposits containing considerable amounts of chlorides. (2) The presence of carbide phases is detrimental to the hot corrosion resistance of both Ni and Co alloys. (3) The complex alloy compositions characteristic of superalloys result in susceptibility to hot corrosion, the extent of which is sensitive to salt composition, particularly for Ni-base alloys. (4) Conclusion 3 suggests that uncoated alloys will not be able to provide the require combination of corrosion resistance and high-temperature strength for any of the components in turbines running on coal gas. (5) Several alloys including Co-18Cr-6Al-1Hf, Co-27Cr, Co-20Ni-27Cr, Ni-50Cr, and Fe-18Cr-6Al-Hf have corrosion resistance for use as coatings and claddings at high temperatures (900 to 1000/sup 0/C). (6) The problem of low temperature hot corrosion (700 to 800/sup 0/C) must still be investigated for the types of deposits likely to form in coal fired systems before selection of reliable coatings can be made.

• Research Organization: Pittsburgh Univ., PA (USA). Dept. of Metallurgical and Materials Engineering
• DOE Contract Number: AC01-79ET13547
• OSTI ID: 5253538
• Report Number(s): DOE/ET/13547-T1
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010600* -- Coal
Lignite
& Peat-- Properties & Composition
36 MATERIALS SCIENCE
360105 -- Metals & Alloys-- Corrosion & Erosion
ALKALI METAL COMPOUNDS
ALLOYS
CHALCOGENIDES
CHEMICAL REACTIONS
CHEMISTRY
CHLORIDES
CHLORINE COMPOUNDS
COATINGS
COBALT
COBALT ALLOYS
COBALT BASE ALLOYS
CORROSION
DEPOSITS
DIAGRAMS
ELEMENTS
GAS TURBINES
HALIDES
HALOGEN COMPOUNDS
HYDROGEN COMPOUNDS
HYDROGEN SULFIDES
HYDROXIDES
IRON ALLOYS
IRON BASE ALLOYS
LEAD
MACHINERY
MATERIALS
METALLOGRAPHY
METALS
MOLTEN SALTS
MOLYBDENUM
NICKEL
NICKEL ALLOYS
NICKEL BASE ALLOYS
OXIDES
OXYGEN COMPOUNDS
PHASE DIAGRAMS
POTASSIUM COMPOUNDS
POTASSIUM SULFATES
REFRACTORY METALS
SALTS
SODIUM COMPOUNDS
SODIUM SULFATES
SULFATES
SULFIDATION
SULFIDES
SULFUR COMPOUNDS
SULFUR DIOXIDE
SULFUR OXIDES
SURFACE PROPERTIES
SURFACE TENSION
TRANSITION ELEMENTS
TURBINE BLADES
TURBINES
TURBOMACHINERY
VANADIUM
WETTABILITY