Abstract
There are over 1000 biomass boilers and about 500 plants
using waste as fuel in Europe, and the numbers are
increasing. Many of them encounter serious problems with
high-temperature corrosion due to detrimental elements
such as chlorides, alkali metals, and heavy metals. By
HVOF spraying, it is possible to produce very dense and
well-adhered coatings, which can be applied for corrosion
protection of heat exchanger surfaces in biomass and
waste-to-energy power plant boilers. Four HVOF coatings
and one arc sprayed coating were exposed to actual
biomass co-fired boiler conditions in superheater area
with a probe measurement installation for 5900 h at 550
and 750 °C. The coating materials were Ni-Cr, IN625,
Fe-Cr-W-Nb-Mo, and Ni-Cr-Ti. CJS and DJ Hybrid spray guns
were used for HVOF spraying to compare the corrosion
resistance of Ni-Cr coating structures. Reference
materials were ferritic steel T92 and nickel super alloy
A263. The circulating fluidized bed boiler burnt a
mixture of wood, peat and coal. The coatings showed
excellent corrosion resistance at 550 °C compared to the
ferritic steel. At higher temperature, NiCr sprayed with
CJS had the best corrosion resistance. IN625 was consumed
almost completely during the exposure at 750 °C.
| Original language | English |
|---|---|
| Pages (from-to) | 194-205 |
| Journal | Journal of Thermal Spray Technology |
| Volume | 24 |
| Issue number | 1-2 |
| DOIs | |
| Publication status | Published - 2015 |
| MoE publication type | A1 Journal article-refereed |
Keywords
- boiler materials
- corrosion resistance
- high-temperature oxidation
- HP/HVOF
- Ni-Cr