A test of adding oxygen into feed-water treatment has been carried out on one supercritical 600 MW unti.Through measuring the growth rate of oxide skin formed in the superheater

as well as analysing the micro-structure and the variation of composition in the said oxide skin

it shows that the adding oxygen into feed-water treatment hadn't quickened the growth rate of oxide skin formed in the superheaters made from T23 and T91 steel materials

and hadn't promoted the fall-off of said oxide skin

however

in superheater made from TP347H steel

the adding oxygen into feed-water treatment boasts effect to promote the peel-off of oxide skin

where as the key of control is controlling the temperature during start-up and shutdown of unit

therefore

in the process of using the above-mentioned treatment to inhibit corrosion of the superheater

the most crucial problem is to control the fall-off of oxide skin in vast amount from stainless steel tubes after using the adding oxygen treatment.