LOW-ALLOY STEEL PETROLEUM TUBE Russian patent published in 2018 - IPC C22C38/32 C21D9/08 

FIELD: manufacturing technology.

SUBSTANCE: invention relates to the production of steel pipes, in particular pipes for oil and gas wells. Oilfield pipe made of low-alloy steel, containing, in mass %, C 0.25–0.35; Si 0.05–0.50; Mn 0.10–1.50; Cr 0.40–1.50; Mo 0.40–2.00; V 0.05–0.25; Nb 0.010–0.040; Ti 0.002–0.050; soluble Al 0.005–0.10, N 0.007 or less, B 0.0001–0.0035, Ca 0–0.005 %, Fe and impurities – balance. In the microstructure of the pipe, the number of cementite particles, each having an equivalent circular diameter of 200 nm or more, is 100 particles/100 mcm² or more.

EFFECT: above-mentioned low-alloy steel oil pipeline has a yield strength of 793 MPa or more, high strength, and excellent resistance to hydrogen sulfide stress corrosion cracking.

1 cl, 4 tbl, 1 dwg