Steam-water corrosion kinetics of steels for a supercritical once-through steam generator

In order to estimate the velocity of steam-water corrosion of steels used in once-through steam generators working under supercritical conditions it is expedient to relate the extra hydrogen content on a separate section of the generator to the inner surface area of the pipes, thus calculating the so called ''hydrogen number'', which indicates how many micrograms of hydrogen has formed on 1 m2 inner surface of the pipes of the steam generator section during an hour at the given consumption of the steam-water mixture. The value obtained may be used for estimation of the overall corrosion rate. The rate of corrosion increases with temperature. For instance, as the temperature of the medium is raised from 260-280 deg C to 460-480 deg C the rate of steam-water corrosion of 12KhMF steel has increased from 4-7 to 26-55 mg Fe/m2xhour, i.e. 6-8 times, displaying exponential growth. Determining the places where hydrogen content considerably increases makes it possible to reveal the sections of the generator which suffer the most intense steam-water corrosion