Tashkent, Mart 4-5, 2022 1-я международная научная конференция «Современное материаловедение: актуальные проблемы, достижении и инновации» Zamonaviy materialshunoslik: dolzarb

"Modern Materials Science: Topical Issues, Achievements and Innovations" (ISCMMSTIAI-2022) 
360 
For this, samples from hydrotransports (steel 20) were cut on various emergency (due to 
corrosion) sections. The overwhelming majority of metal damage as a result of internal corrosion 
occurs on supply hydrotransports, so the samples were taken from such pipes. The outer corrosion 
of the selected hydrotransports is insignificant, therefore, the weight loss of the metal pipe from the 
outside is extremely small, which made it possible with the help of a gravimetric method to 
challenge the rate of internal corrosion. 
The calculation of the rate of internal corrosion by substitution to the calculated formulas of 
values of
τ
t
, t, pH, h, d
i
, G corresponding to the working conditions of the surveyed areas. The 
values of the parameters T, the pH was taken as the average per year, and the G value remained 
constant during the entire period of operation. The average annual calculated values of the 
parameter K are in the range of 0.01 - 0.07 mm/year. 
The nature of the change in the internal corrosion rate in the range of 8.0 <
p
H <10.0 at the 
average annual temperature of the modified dispersed systems 20 ° C is shown in Fig. 2. Corrosion 
rate at normalized values
pH
= 9.6 - 10.0 is almost equal to zero and exponentially grows with a 
decrease in the 
pH
. 
The calculation according to formula (2) gives an estimate of the intensity of uniform wear of the 
hydrotransports. However, in real conditions of operation of hydrotransports at 
pH 
<9.5 corrosion 
of carbon steel pipes, a local character is wearing a local character (the reasons are the increased 
content of Cl
-
and ЅО
4
2-
, ions, the heterogeneity of iron oxide films on the surface of the steel and 
the presence of pairs of uneven aerations, non-metallic inclusions and dislocations). It is the local 
corrosion that is the main cause of emergency stopping of the portions of hydrotransports.