mechanical properties of tubes and promotes formation of disperse carbides;
• physical-chemical properties of oil and gas production media in Ukraine and
abroad [1-3], in particular, content of corrosive components such as chlorides, carbon
dioxide, hydrogen sulfide, etc.;
• the results of corrosion tests of specially melted in laboratory conditions and hot-
worked experimental low-carbon low-alloy steels containing 1...2 % Cr and micro
alloying additives (V and Nb) conducted in the oil production media;
• thermal and deformation conditions of hot tube rolling on the structure of ferrite-
perlite steels [8];
• data on the rolling and thermal equipment configuration at tube plants in
Ukraine, in particular, YuTiST CJSC Steel Tube Plant, Nikopol; INTERPIPE NTZ
LLC, Dnipro; INTERPIPE Niko-Tube LLC, Nikopol.
Gravimetric corrosion tests of the specimens taken from laboratory smelted steel
heats in highly mineralized stratal water containing up to 150 g/l chlorides taken from
Anastasivske deposit of Okhtyrkanaftogaz NGVU, Sumy region, Ukraine (Table 2)
have shown that alloying with chromium has a significant effect on steel corrosion
resistance (Table 3). When testing for 288 hours (12 days) in corrosive stratal water,
specimens of tested steels containing 1-2% Cr have shown on average 3-4 times lower
corrosion rates, hence higher corrosion resistance compared with the tube specimens
of steel 20 (GOST 8732). At the same time, there was a decrease in the rate of corrosion
of the specimens taken from experimental low-alloy steels and an increase in the rate
of corrosion of tube specimens of steel 20 (Table 3).
Table 2 Structure of stratal water at Anastasіvske deposit
Density,
g/cm
3
рН
Ion content, g/l
Total
mineralizati
on, g/l
Gas content, mg/l
t, С /
Р, МPа
Cl
-
HCO
3
-
other
Н
2
S
СО
2
О
2
1.12-1.15
4.8-
6.2
93.7-
146.8
0.12-0.22
56.9-
89.3
150.9-235.7
4.8
58.2
1.0
15-50 /
6-11
Table 3 Results of corrosion studies of specimens of low-alloy steels taken from
experimental heats
Steel grade
Corrosion rate, mm/yr and test duration (hours)
72
168
288
Welded joint
20
1.53
1.62
1.89
1.6…1.93
06Cr1
0.067
0.063
0.047
0.071…0.073
06Cr1V
0.075
0.072
0.063
0.074…0.077
06Cr1Nb
0.064
0.061
0.048
0.069…0.072
06Cr2
0.63
0.060
0.046
0.073…0.078
Authors of the study [6] explain significant increase in corrosion resistance of the
steel alloyed with 0.5-2 % chromium by migration of chromium from the steel body to
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