Environmental effects on molten chloride accelerated corrosion in waste incineration systems

Book · Fri Dec 01 04:00:00 EST 1995

OSTI ID:128735

Takemura, M; McNallan, M J ^[1]

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1. Univ. of Illinois, Chicago, IL (United States)

To simulate corrosion of superheater tubes in waste incinerators, the effects of gas mixtures of Cl{sub 2}-O{sub 2} and HCl-O{sub 2}-H{sub 2}O and KCl deposit on corrosion of C1010 low carbon steel at 400 C were examined by using thermogravimetric analysis. In 0.2%0.5/2%Cl{sub 2}-1%O{sub 2}-bal. Ar, accelerated corrosion occurred, and followed by mass decrease. In 0.2%Cl{sub 2}-1%O{sub 2}-bal. Ar, the top layer of scale was Fe{sub 3}O{sub 4}, which had a different morphology from that produced in environments without KCl, and beneath the Fe{sub 3}O{sub 4} layer more K and Cl was detected. Accelerated corrosion would be hot corrosion by molten eutectic salt of KCl and FeCl{sub 2}, by chlorination of iron. Fe{sub 3}O{sub 4} would be precipitated from the molten salt because of higher oxygen potential at the gas/scale interface than the metal/scale interface. Volatilization of chloride would be the reason for the mass decrease. In 0.2%HCl-1%O{sub 2}-2%H{sub 2}O-bal. Ar, accelerated corrosion did not occur. However, by eliminating O{sub 2} from the gas system, accelerated corrosion was seen. The main corrosion product was Fe{sub 3}O{sub 4}. The accelerated corrosion could also be explained by hot corrosion by KCl-FeCl{sub 2} molten eutectic salt. It did not occur in 0.2%HCl-1%O{sub 2}-2%H{sub 2}O-bal. Ar probably because the chlorine potential was too small to produce enough FeCl{sub 2}.

• OSTI ID: 128735
• Report Number(s): CONF-950304--
• Country of Publication: United States
• Language: English

Related Subjects

09 BIOMASS FUELS
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
36 MATERIALS SCIENCE
ARGON
CHLORINE
COMBUSTION
CORROSION
EXPERIMENTAL DATA
HYDROCHLORIC ACID
MUNICIPAL WASTES
OXYGEN
PHASE DIAGRAMS
POTASSIUM CHLORIDES
SCANNING ELECTRON MICROSCOPY
SIMULATION
SPECTROSCOPY
STEELS
SUPERHEATERS
THERMAL GRAVIMETRIC ANALYSIS
X-RAY DIFFRACTION