(КПІ ім. Ігоря Сікорського; ТОВ «Українська водна спілка», 2021) Vasyliev, G.
The mild steel corrosion has been studied in hot tap water (50 C) using linear polarization
technique in the laboratory set-up that models water circulating system. The influence of water flow
rate (0.15-0.45 m/s) and water supply rate (0-70 % of system volume per hour) on corrosion
kinetics have been investigated. The corrosion products, formed on the surface of the steel
corrosion probes, have been analysed with X-Ray Diffraction (XRD). It has been found, that in
condition of low water flow rate (0.15 m/s) and in the absence of water supply the corrosion rate is
high (0.29 mm/year) due to low blocking abilities of the surface deposits. Amorphous Fe(OH)3 is
the main corrosion product to be detected on the surface. The increase in water flow rate above
0.15 m/s and water supply rate above 30 % of system volume per hour leads to the 1.6 times
corrosion rate reduction (to 0.18 mm/year) due to the formation of dense surface layer of calcium
carbonate and iron oxyhydroxides. The results obtained can be utilized to improve the corrosion
performance of hot water supply systems.