Simulating test results for fireside corrosion of superheater and reheater tubes operated at advanced steam condition in coal-fired boilers

Conference · · TMS (The Metallurgical Society) Paper Selection; (USA)

OSTI ID:5464508

Ohtomo, A; Aoki, H; Ando, S ^[1]

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1. Ishikawajima-Harima HI Co., Ltd., Tokyo (Japan)

Coal ash corrosion of superheater and reheater tubes is very severe problem in the advanced steam condition boiler operated at super high pressure and temperature. Various corrosion tests have been performed to help select the best tube material for this application and clarify the corrosion mechanism. These include isothermal coal-ash-coated coupon tests in synthetic at 550-750 C, temperature gradient tests involving ash coated, air-cooled tubes exposed to 1200-1400 C flue gases, electrochemical evaluations of coal ash corrosion, and probe tests in actual coal-fired boilers employing 2.2% S bearing coal. The synthetic coal ash used consisted of 37.5 Mol% Na{sub 2}SO{sub 4}, 37.5 Mol% K{sub 2}SO{sub 4} and 25 Mol% Fe{sub 2}O{sub 3}. The synthetic flue gases consisted of 14% CO{sub 2}, 4% O{sub 2}, either 0.26 or 1.0% SO{sub 2}, balance N{sub 2}. Results for these various tests indicate that the most severe temperature for corrosion is around 700 C, dependent upon flue gas SO{sub 2} content. Gradient tests show that corrosion occurs only in the range 600-750 C. AISI 347H was found to exhibit a negligible corrosion rate in the probe tests, even at 650 C.

• OSTI ID: 5464508
• Report Number(s): CONF-840909--
• Conference Information: Journal Name: TMS (The Metallurgical Society) Paper Selection; (USA) Journal Volume: 56
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
014000* -- Coal
Lignite
& Peat-- Combustion
36 MATERIALS SCIENCE
360105 -- Metals & Alloys-- Corrosion & Erosion
ALKALI METAL COMPOUNDS
ALLOYS
ASHES
AUSTENITIC STEELS
BOILERS
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CARBONACEOUS MATERIALS
CHALCOGENIDES
CHEMICAL REACTIONS
CHROMIUM ALLOYS
CHROMIUM-NICKEL STEELS
COAL
COMBUSTION
CORROSION
CORROSION RESISTANCE
CORROSION RESISTANT ALLOYS
CORROSIVE EFFECTS
ELEMENTS
ENERGY SOURCES
FLUE GAS
FOSSIL FUELS
FUELS
GASEOUS WASTES
HEAT RESISTANT MATERIALS
HEAT RESISTING ALLOYS
HIGH ALLOY STEELS
IRON ALLOYS
IRON BASE ALLOYS
IRON COMPOUNDS
IRON OXIDES
MATERIALS
MATERIALS TESTING
NICKEL ALLOYS
NIOBIU
NITROGEN
NONMETALS
OXIDATION
OXIDES
OXYGEN
OXYGEN COMPOUNDS
POTASSIUM COMPOUNDS
POTASSIUM SULFATES
RESIDUES
SIMULATION
SODIUM COMPOUNDS
SODIUM SULFATES
STAINLESS STEEL-347
STAINLESS STEELS
STEEL-CR18NI11NB
STEELS
SULFATES
SULFUR COMPOUNDS
SULFUR CONTENT
SULFUR DIOXIDE
SULFUR OXIDES
SUPERHEATERS
TEMPERATURE DEPENDENCE
TEMPERATURE GRADIENTS
TESTING
THERMOCHEMICAL PROCESSES
TRANSITION ELEMENT COMPOUNDS
WASTES