FORGED PART FROM STEEL AND METHOD OF MANUFACTURING THEREOF Russian patent published in 2024 - IPC C22C38/60 C22C38/42 C22C38/44 C22C38/46 C22C38/48 C22C38/50 C22C38/54 C22C38/58 C21D1/18 C21D6/00 C21D7/13 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, namely to a forged mechanical automotive part made of steel. Steel contains the following elements, expressed in wt.%: 0.04 ≤ C ≤ 0.28, 1.2 ≤ Mn ≤ 2.2, 0.3 ≤ Si ≤ 1.2, 0.5 ≤ Cr ≤ 1.5, 0.01 ≤ Ni ≤ 1, 0 ≤ S ≤ 0.06, 0 ≤ P ≤ 0.02, 0 ≤ N ≤ 0.015, optionally, at least one component selected from: 0 ≤ Al ≤ 0.1, 0.03 ≤ Mo ≤ 0.5, 0 ≤ Cu ≤ 0.5, 0.04 ≤ Nb ≤ 0.15, 0.01 ≤ Ti ≤ 0.1, 0 ≤ V ≤ 0.5, 0.0015 ≤ B ≤ 0.004, 0 ≤ Sn ≤ 0.1, 0 ≤ Ce ≤ 0.1, 0 ≤ Mg ≤ 0.010 and 0 ≤ Zr ≤ 0.010, the rest of the composition consists of iron and unavoidable impurities. Steel has a microstructure consisting in area fractions of 55–80% martensite, 20–45% of auto-tempering martensite and 0–10% of residual austenite, wherein the total amount of auto-tempering martensite and martensite is at least 90%. Part has tensile strength of 1300 MPa or more and impact strength higher than or equal to 38 J/cm² at 20 °C.

EFFECT: production of automotive parts with required level of mechanical properties without hardness gradient between surface layer and central part.

13 cl, 1 dwg, 4 tbl