Laboratory fire-side corrosion evaluation of improved superheater tube alloys and coatings. Final report. [With addition of aluminium, silicon and manganese]

Technical Report · Wed Jun 01 04:00:00 EDT 1983

OSTI ID:5939030

Rehn, I M

The Fireside Corrosion Test Program was performed as an extension of the previous Fireside Corrosion Study reported in EPRI-CS-1653. The added tests were directed toward the most promising solutions to the fireside corrosion of superheater and reheater tubes exposed to high-alkali coal-burning systems. The test technique was improved by performing repeated exposures using a fresh charge of fireside ash to obtain results equivalent to long-term exposures by retort testing. New alloys showing promise of substantial improvement in corrosion resistance were given high priority. Custom-melted and rolled strips of these modified stainless steels were prepared and tested for comparison with the available commercial stainless steels. The best performing alloys - containing aluminum, silicon, and manganese additions - generated an adherent scale which retarded fireside attack 6 to 10 times better than commercial Type 304, which suffered loss of scale and provided minimal protection from the molten trisulfate attack. Repeated exposures and examination verified that these protective scales would be retained on the experimental alloys. Further testing of the magnesium-zirconate coating and other plasma spray-deposited coatings was done to evaluate coating life. The magnesium-zirconate coating was successful in resisting attack and remaining intact after repeated exposures. The effect of the chromium gradient concentrate did not significantly influence the electrochemical pitting mechanism.

• Research Organization: Foster Wheeler Development Corp., Livingston, NJ (USA)
• OSTI ID: 5939030
• Report Number(s): EPRI-CS-3134; ON: DE83902649
• Country of Publication: United States
• Language: English

Related Subjects

20 FOSSIL-FUELED POWER PLANTS
200104* -- Fossil-Fueled Power Plants-- Components
36 MATERIALS SCIENCE
360105 -- Metals & Alloys-- Corrosion & Erosion
ALKALI METAL COMPOUNDS
ALLOYS
ALUMINIUM
BENCH-SCALE EXPERIMENTS
CHEMICAL COMPOSITION
CHEMICAL REACTIONS
CHROMIUM ALLOYS
CHROMIUM STEELS
CHROMIUM-NICKEL STEELS
COATINGS
CORROSION
CORROSION RESISTANCE
CORROSION RESISTANT ALLOYS
CORROSIVE EFFECTS
DATA
ELEMENTS
EXPERIMENTAL DATA
FOSSIL-FUEL POWER PLANTS
HEAT RESISTANT MATERIALS
HEAT RESISTING ALLOYS
INFORMATION
IRON ALLOYS
IRON BASE ALLOYS
MANGANESE
MATERIALS
MATERIALS TESTING
METALS
MOLTEN SALTS
NICKEL ALLOYS
NIOBIUM
NIOBIUM ADDITIONS
NIOBIUM ALLOYS
NUMERICAL DATA
OXYGEN COMPOUNDS
PITTING CORROSION
POWER PLANTS
PROTECTIVE COATINGS
SALTS
SEMIMETALS
SILICON
STAINLESS STEEL-304
STAINLESS STEEL-310
STAINLESS STEEL-347
STAINLESS STEELS
STEELS
SULFATES
SULFUR COMPOUNDS
SUPERHEATERS
TESTING
THERMAL POWER PLANTS
TRANSITION ELEMENTS
TUBES