Corrosion Analysis of Boiler Tubes from a 100-HP Boiler Burning an Oil Coal Slurry

摘要

A corrosion analysis was performed on segments of ASTM A 178 steel boiler tubes removed from a 75-kW boiler operated by the Pittsburgh Energy Research Center. It burned a coal slurry in No. 6 fuel oil and produced 171 exp 0 C steam. The boiler tubes were exposed to this environment for 1000 h with an operating wall temperature of about 180 exp 0 C. A 76- micrometers thick scale formed on the fire side of these tubes. Exposure of the tubes to atmospheric conditions during boiler disassembly and cyclic boiler conditions prevented estimating the contribution of the flue gas exposure to the scale buildup. However, analysis of this scale indicated that fly ash deposition accounted for less than 5% of the tube weight of the scale. (ERA citation 03:042212)