Erosion resistance of cooled thermal sprayed coatings under simulated erosion conditions at waterwall in FBCs
- Metalspray USA, Inc., Richmond, VA (United States). Metallurgical Lab.
- Morgan State Univ., Baltimore, MD (United States). School of Engineering
The erosion-corrosion (E-C) behavior of cooled 1018 steel and several thermal sprayed coatings by bed ash, retrieved from an operating circulating fluidized bed combustor (CFBC) boiler firing biomass, was determined in laboratory tests using a nozzle type elevated temperature erosion tester. Test conditions attempted but not exactly to simulate the erosion conditions found at the refractory/bare-tube interface at the combustor waterwall of FBC boilers. The specimens were water-cooled on the backside. Material wastage rates were determined from the thickness loss measurements of specimens. Test results were compared with erosion-corrosion test results for isothermal specimens. The morphology of specimens was examined by scanning electron microscopy (SEM). It was found that the cooled specimens demonstrated higher erosion-corrosion wastage than those of the isothermal specimens. At a shallow impact angle of 30{degree} the effect of cooling specimens on the erosion wastage for thermal sprayed coatings was less than that for 1018 steel, while at a steep impact angle of 90{degree} this effect for thermal sprayed coatings was greater than that for 1018 steel. The hypersonic velocity oxygen fuel (HVOF) Cr{sub 3}C{sub 2} ceramic coating exhibited the highest E-C resistance due to its favorable composition and fine structure. The poor E-C resistance of arc-sprayed FeCrSiB coating was attributed to larger splat size, higher porosity and the presence of radial and tangential microcracks within the coating.
- OSTI ID:
- 355833
- Report Number(s):
- CONF-9705116--; ISBN 0-7918-1557-9
- Country of Publication:
- United States
- Language:
- English
Similar Records
Analysis/control of in-bed tube erosion phenomena in the fluidized bed combustion (FBC) system. Quarterly report
The elevated temperature erosion behavior of HVOF tungsten carbide cermet coatings