FIELD: metallurgy.
SUBSTANCE: steel contains, wt %: 0,03 ≤ C < 0.2; Si ≤ 0.49; 3 < Mn ≤ 4; Ni ≤ 0.9; 1 ≤ Cr≤ 5; Mo + W/2 ≤ 1; Cu ≤ 0.9; S + Se/2 + Te/3 < 0.020; Al ≤ 0.1; balance is iron and admixtures that got into steel in process of smelting. To manufacture a part in the form of a block or a sheet, steel is shaped by hot plastic deformation carried out through forging or rolling. Austenisation is carried out, when required, and then further tempering by cooling on air. Produced parts have bainite, martensite-bainite or martensite structure. The difference in hardness between harder and less harder zones of the part due to liquation streaks makes less than approximately 20% of the average part hardness.
EFFECT: steel has improved mechanical properties providing for low deviation of values of specified properties as a result of liquation.
13 cl, 1 dwg, 4 tbl
