Analysis of composite tube cracking in recovery boiler floors
- Oak Ridge National Lab., TN (United States)
- Pulp and Paper Research Inst. of Canada, Vancouver, British Columbia (Canada)
Cracking of co-extruded (generally identified as composite) floor tubes in kraft black liquor recovery boilers was first observed in Scandinavia, but this problem has now been found in many North American boilers. In most cases, cracking in the outer 304L stainless steel has not progressed into the carbon steel, but the potential for such crack propagation is a cause of concern. A multidimensional study has been initiated to characterize the cracking seen in composite floor tubes, to measure the residual stresses resulting from composite tube fabrication, and to predict the stresses in tubes under operating conditions. The characterization studies include review of available reports and documents on composite tube cracking, metallographic examination of a substantial number of cracked tubes, and evaluation of the dislocation structure in cracked tubes. Neutron and X-ray diffraction are being used to determine the residual stresses in composite tubes from two major manufacturers, and finite element analysis is being used to predict the stresses in the tubes during normal operation and under conditions where thermal fluctuations occur.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC05-96OR22464
- OSTI ID:
- 383558
- Report Number(s):
- CONF-9609222-1; ON: DE96013784; TRN: AHC29621%%1
- Resource Relation:
- Conference: Technical Association of Pulp Paper Institute (TAPPI) engineering conference, Chicago, IL (United States), 15-19 Sep 1996; Other Information: PBD: [1996]
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
36 MATERIALS SCIENCE
BOILERS
TUBES
CRACK PROPAGATION
RESIDUAL STRESSES
THERMAL STRESSES
STAINLESS STEEL-304L
PAPER INDUSTRY
CARBON STEELS
STRESS ANALYSIS
METALLOGRAPHY
NEUTRON DIFFRACTION
SPENT LIQUORS
MICROSTRUCTURE
PITTING CORROSION
EXPERIMENTAL DATA