Alloy 33 weld overlay extends boiler tube life and saves money
- ThyssenKrupp VDM (United States)
Low-NOx burners installed in coal-fired utility boilers cause problems with boiler tube cracking. Materials with increased corrosion resistance such as the new Alloy 33 should be more resistant to this type of 'circumferential cracking'. Alloy 33 is cheaper and has lower nickel and molybdenum content than the traditional Alloy 622 and 625. The article describes extensive corrosion testing experiments carried out by ThyssenKrupp VDM on Alloy 33 and Alloy 622. In the lab, in environments representative of coal-fired boilers operating under low-NOx combustion conditions, Alloy 33 was found to be better than Alloy 622. Field tests compared Alloy 33 and Alloy 622 in two supercritical tangentially-fired boilers and one tangentially-fired high pressure drum boiler. After up to 23 months of exposure there was no evidence of cracks and only slight evidence of corrosion in Alloy 33. 1 fig., 2 tabs., 2 photos.
- OSTI ID:
- 21004915
- Journal Information:
- Power Engineering (Barrington), Vol. 111, Issue 9; ISSN 0032-5961
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
36 MATERIALS SCIENCE
BOILERS
TUBES
SERVICE LIFE
COAL
FOSSIL-FUEL POWER PLANTS
NITROGEN OXIDES
STAGED COMBUSTION
CORROSION RESISTANT ALLOYS
BURNERS
CHROMIUM ALLOYS
IRON ALLOYS
NICKEL ALLOYS
MATERIALS TESTING
WELDING
WIRES
COST
BENCH-SCALE EXPERIMENTS
FIELD TESTS
CRACKS
INHIBITION
LIFETIME EXTENSION
SUPERCRITICAL STATE