Tubing wastage in fluidized-bed coal combustors (TVA, 20 megawatt AFBC Pilot Plant)

Technical Report · Fri Apr 07 00:00:00 EDT 1989

DOI:https://doi.org/10.2172/5881048· OSTI ID:5881048

Witherell, C. E.

Study of TVA tubing samples representing both wastage-susceptible and wastage-resistant tube banks has indicated a wastage mechanism similar to that identified in previously-studied tube samples from Grimethorpe (UK). Metallurgical differences between the two TVA tube banks were also observed that are believed relevant to their wastage response. Wastage appears to occur through exfoliation of protective oxide scale caused by impingement and abrasion of fluidized bed materials. There is no evidence that chemical effects of elements such as sulfur or chlorine are responsible for or contribute to the wastage process. The tube from the wastage-resistant tube bank, in contrast to the tubes that experienced wastage, formed an alloy-enriched layer at the scale/substrate interface that is apparently oxidation resistant and seems to protect the steel surface from mechanical impacts and abrasion of bed materials. 47 refs., 22 figs., 2 tabs.

• Research Organization: Lawrence Livermore National Lab., CA (USA)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 5881048
• Report Number(s): UCRL-21163; ON: DE89016653
• 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
CHEMICAL REACTIONS
COATINGS
COMBUSTORS
COMPARATIVE EVALUATIONS
CORROSION
CRYSTAL STRUCTURE
EROSION
FLUIDIZED-BED COMBUSTORS
IRON ALLOYS
IRON BASE ALLOYS
METALLURGICAL EFFECTS
MICROSTRUCTURE
OXIDATION
PROTECTIVE COATINGS
SCALING
STEELS
TUBES