Improved materials for coal-fired boiler superheater and reheater tubes subjected to fireside corrosion

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

OSTI ID:5323925

Rehn, I M ^[1]

---

1. Foster Wheeler Development Corp., Livingston, NH (USA)

A laboratory test program (funded by EPRI and FWDC) was conducted to develop improved corrosion resistant alloys for superheater and reheater tubes in direct coal-fired steam generators - operating at higher temperatures than currently in use. The program consisted of a broad literature review and laboratory evaluation of 19 commercial and semicommercial alloys, 19 custom-melted alloys and 18 types of high-temperature coatings which were subjected to flowing flue gas and molten alkali-iron trisulfate ash at 675 and 790 C. Almost all commercial and semicommercial alloys suffered severe attack and pitting under the laboratory fireside test environment at 675 C. Several experimental alloys showing promise of substantial improvement in corrosion resistance were evaluated for potential applications as a cladding or as a high alloy, wrought tube. The best performing austenitic alloys - containing aluminum, silicon, and manganese additions - generated an adherent scale which retarded fireside attack 6 to 10 times better than commercial Type 304 stainless steel, which suffered loss of scale and provided minimal protection from the molten trisulfate attack.

• OSTI ID: 5323925
• 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
ALLOYS
ALUMINIUM ADDITIONS
ALUMINIUM ALLOYS
ASHES
AUSTENITIC STEELS
BENCH-SCALE EXPERIMENTS
BOILERS
CARBONACEOUS MATERIALS
CHEMICAL REACTIONS
CHROMIUM ALLOYS
CHROMIUM-NICKEL STEELS
COAL
COMBUSTION
COMPARATIVE EVALUATIONS
CORROSION
CORROSION RESISTANCE
CORROSION RESISTANT ALLOYS
CORROSIVE EFFECTS
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 SULFATES
MANGANESE ADDITIONS
MANGANESE ALLOYS
MATERIALS
MOLTEN SALTS
NICKEL ALLOYS
OXIDATION
OXYGEN COMPOUNDS
PITTING CORROSION
RESIDUES
SALTS
SILICON ADDITIONS
SILICON ALLOYS
STAINLESS STEEL-304
STAINLESS STEELS
STEAM GENERATORS
STEEL-CR19NI10
STEELS
SULFATES
SULFUR COMPOUNDS
SUPERHEATERS
TEMPERATURE DEPENDENCE
THERMOCHEMICAL PROCESSES
TRANSITION ELEMENT COMPOUNDS
VAPOR GENERATORS
WASTES