"high-temperature corrosion"
Question:
"In my power plant,there are four coal-fired boilers of which high-temperature corrosion occured on waterwall tube.The corrosion product included lead(Pb),Zn,S,Fe elements.what did Pb and Zn and S do duing the high-temperature corrosion procedure."
Answer:
The influence of the O.D. deposit elements you mentioned depend on the estimated tube metal temperature of the waterwall tube. Most fire ash corrosion is caused by compounds that melt at the temperature of interest. Typically, chlorides form low melting compounds that cause O.D. wastage. Sulfides also form low melting point compounds. Lead (as lead oxide) is a high melting point compound and may not have any effect on corrosion. You need to determine the compound form of the elements on the tube O.D. and determine their melting points in relation to the metal temperature of the boiler tube.