| Abstrakt: |
To reveal the high-temperature corrosion mechanism of heating surfaces in the typical flue gas environment in the municipal solid waste incineration (MSWI) system, samples of 310S alloy, a commonly used boiler superheater heating surface material, were deposited with NaCl/50 wt.% K2SO4 and exposed to a typical MSWI flue gas atmosphere of 7% O2 + 600 ppm HCl + 100 ppm SO2 + N2 at 460, 510, 550, and 580 °C for 168 h for corrosion test. The macroscopic morphology, corrosion kinetics, phase composition of corrosion products, and the distribution and content of elements in the corrosion section were analyzed. Our results showed that the NaCl/50 wt. % K2SO4 salt mixture was an extremely corrosive reagent, and its corrosiveness was enhanced with the increase in temperatures. At 460 °C, the salt mixture did not melt, and the corrosion was induced by the reactions between alkali chlorides and alloy, plus the "active oxidation" catalyzed by chlorine. At 510–580 °C, the salt mixtures were completely melted, considerable metal chlorides and some metal sulfides were detected in corrosion products, and the corrosion was controlled by "electrochemical" reactions within the molten salt, coupled with the "active oxidation". These findings provide new insights into high-temperature corrosion phenomena in MSWI plants. [ABSTRACT FROM AUTHOR] |
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