Coal ash corrosivity index for high-temperature alloys

Journal Article · Sun Feb 01 04:00:00 EST 1987 · Mater. Compon. Fossil Energy Appl.; (United States)

OSTI ID:5756918

A method for estimating the corrosion rates of several high temperature alloys in a coal combustion atmosphere has been developed from an extensive study of boiler deposits, test probe deposits, and corrosion coupons exposed to synthetic coal ash in the laboratory. Deposits from 11 locations in a utility boiler - ranging from the lower furnace walls to the electrostatic precipitator entrance - were analyzed. The chemical composition of the deposits was compared with that of the coal ash. In addition, laboratory tests were conducted on Type 347 H stainless steel using salt mixtures to simulate deposits found in the boilers and in a typical coal combustion gas atmosphere. These tests demonstrated that the sodium and the potassium in the deposits promote corrosion and the calcium and magnesium inhibit corrosion. The SO/sub 2/ content of the combustion gas also was shown to affect the corrosion process. The contribution of each of the corrosive and inhibitive components was determined in separate experiments. These experimental results led to an expression for the high temperature corrosion of Type 347H stainless steel under conditions likely to be experienced by secondary superheaters and reheaters. 4 figures.

• OSTI ID: 5756918
• Journal Information: Mater. Compon. Fossil Energy Appl.; (United States), Journal Name: Mater. Compon. Fossil Energy Appl.; (United States) Vol. 66; ISSN MCFAD
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010800 -- Coal
Lignite
& Peat-- Waste Management
014000* -- Coal
Lignite
& Peat-- Combustion
36 MATERIALS SCIENCE
360105 -- Metals & Alloys-- Corrosion & Erosion
ALKALI METALS
ALKALINE EARTH METALS
ALLOYS
ALUMINIUM ALLOYS
ASHES
BOILERS
CALCIUM
CARBONACEOUS MATERIALS
CHALCOGENIDES
CHEMICAL COMPOSITION
CHEMICAL REACTIONS
CHROMIUM ALLOYS
CHROMIUM STEELS
CHROMIUM-NICKEL STEELS
COAL
COBALT ALLOYS
COMBUSTION
CORROSION
CORROSION RESISTANT ALLOYS
CORROSIVE EFFECTS
DEPOSITS
ELEMENTS
ENERGY SOURCES
FOSSIL FUELS
FUELS
HEAT RESISTANT MATERIALS
HEAT RESISTING ALLOYS
INCOLOY ALLOYS
INCONEL 617
INCONEL ALLOYS
IRON ALLOYS
IRON BASE ALLOYS
MAGNESIUM
MATERIALS
MATHEMATICAL MODELS
METALS
MOLYBDENUM ALLOYS
NICKEL ALLOYS
NICKEL BASE ALLOYS
NIOBIUM ADDITIONS
NIOBIUM ALLOYS
OXIDATION
OXIDES
OXYGEN COMPOUNDS
POTASSIUM
RESIDUES
SODIUM
STAINLESS STEEL-310
STAINLESS STEEL-316
STAINLESS STEEL-321
STAINLESS STEEL-347
STAINLESS STEELS
STEELS
SULFUR COMPOUNDS
SULFUR DIOXIDE
SULFUR OXIDES
SUPERHEATERS
THERMOCHEMICAL PROCESSES
TITANIUM ADDITIONS
TITANIUM ALLOYS