Adopting energy dispersion spectroscopic analyser(EDS) and X-ray photoelectron spectroscopic analyser(XPS)

the element compositions

valence

and relative contents of yellow depositions obtained from the surface of first 1~5 HP grade turbine vanes have been analysed.Results show that the yellow depositions were a mixture of sulfate or silicate

which contains elements as oxygen

calcium

sulfer

silicon

iron

magnesium

and sodium.It is believed from analysis that these substances were introduced from outside of the system by leakage

for example

some salts of calcium and magnesium introduced from condenser leakage would deposit on the surface of turbine vanes during water-vapor circulation.