STEEL FOR FLEXIBLE PUMP AND COMPRESSOR PIPE, CHARACTERIZED BY SMALL RATIO BETWEEN THE YIELD LIMIT AT TENSION AND STRENGTH UNDER TENSION AND SUPER HIGH STRENGTH AND EXTRA HIGH STRENGTH, METHOD FOR OBTAINING IT Russian patent published in 2021 - IPC C22C38/58 C22C38/50 C21D8/02 

FIELD: metallurgy.

SUBSTANCE: invention relates to the field of metallurgy, namely the manufacture of steel for coiled tubing. Steel has the following chemical composition, in wt%: C: 0.05-0.16, Si: 0.1-0.9, Mn: 1.25-2.5, P: ≤0.015, S: ≤0.005 , Cr: 0.51-1.30, Nb: 0.005-0.019, V: 0.010-0.079, Ti: 0.01-0.03, Mo: 0.10-0.55, Cu: 0.31-0,60, Ni: 0.31-0.60, Ca: 0.0010-0.0040, Al: 0.01-0.05, N: ≤0.008, the rest is Fe and inevitable impurities. The steel has a tensile yield strength (R_p0.2) of 620 MPa or more, a tensile strength (R_m) of 750 MPa or more, an elongation (A₅₀) of 11% or more, and a ratio between the yield strength at and a tensile strength (R_p0.2/R_m) of 0.83 or less.

EFFECT: provides for obtaining tubing of the required strength.

5 cl, 3 tbl, 1 dwg