METHOD OF PRODUCING STEEL PART AND CORRESPONDING STEEL PART Russian patent published in 2020 - IPC C21D8/06 C21D9/52 C22C38/04 C21D8/00 

FIELD: metallurgy.

SUBSTANCE: invention relates to the field of metallurgy. Proposed method comprises casting of steel containing the following, wt%: 0.10 %≤C≤0.35 %, 0.8 %≤Si≤ 2.0 %, 1.8 %≤Mn≤2.5 %, P≤0.1 %, 0 %≤S≤0.4 %, 0 %≤Al≤1.0 %, N≤0.015 %, 0 %≤Mo≤0.4 %, 0.02 %≤Nb≤0.08 %, 0.02 %≤Ti≤0.05 %, 0.001 %≤B≤0.005 %, 0.5 %≤Cr≤1.8 %, 0 %≤V≤0.5 %, 0 %≤Ni≤0.5 % to obtain a semi-finished product, hot rolling of the semi-finished product at initial hot rolling temperature higher than 1,000 °C and cooling the product air to room temperature to obtain a hot-rolled steel part having a microstructure consisting of 70–90 % bainite, from 5 % to 25 % of M/A and at most 25 % martensite, wherein the bainite and the M/A compounds containing as much residual austenite that the total content of the residual austenite in the steel is between 5 % and 25 %, wherein the content of carbon in the residual austenite is between 0.8 % and 1.5 %.

EFFECT: improved mechanical properties of the part.

20 cl, 3 tbl