STRUCTURAL STEEL WITH BAINITIC STRUCTURE, OBTAINED FROM IT FORGED PARTS AND METHOD OF FORGED PART PRODUCTION Russian patent published in 2019 - IPC C22C38/58 C21D8/00 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, particularly, to heat treatment of steel. To ensure technical result structural steel contains, wt%: up to 0.25 C, up to 0.45 Si, 0.20–2.00 Mn, up to 4.00 Mn, 0.6–3.0 Mo, 0.004–0.020 N, up to 0.40 S, 0.001–0.035 Al, 0.0005–0.0025 B, up to 0.015 Nb, up to 0.01 Ti, up to 0.10 V, up to 1.5 Ni and up to 2.0 Cu, iron and unavoidable impurities – the rest, with the following condition: %Al/27+%Nb/45+%Ti/48+%V/25>%N/3.75. Structural steel has yield strength of at least 750 MPa, tensile strength of at least 950 MPa and a structure containing at least 80 vol% bainite and maximum total amount of residual austenite, ferrite, perlite and/or martensite of 20 vol%. Steel is used, in particular, for production by means of forging of forged parts, having along their length significant changes in cross section. Invention also discloses a method of making forged parts.

EFFECT: high strength and low tendency to deformation.

15 cl, 2 tbl