The feedwater chemistry is critical to the overall corrosion and reliability of the fossil fired generating
units. The effect of dissolved oxygen on corrosion of carbon steels in feedwater system is analyzed. The
corrosion experiments of boiler tube steels in supercritical water containing different dissolved oxygen
are carried out. The different effect mechanics of dissolved oxygen on corrosion in different parts of steam–
water systemare defined. Flowaccelerated corrosion in lowtemperature feedwater system can be controlled
by dissolved oxygen, but dissolved oxygen can accelerate failure of boiler tubes at high temperature from
three aspects: corrosion rate, crack growth rate of SCC, and evaporating consumption rate of chromium.
Considering the corrosion of the whole steam–water system, a more effective feedwater chemistry treatment
method is proposed.