PROCEDURE FOR PRODUCTION OF STEEL SHEET WITH SUPER-HIGH CHARACTRISTICS OF TENSILE STRENGTH, PLASTICITY AND IMPACT STRENGTH AND SHEET FABRICATED BY THIS PROCEDURE Russian patent published in 2010 - IPC C22C38/38 C22C38/34 C22C38/30 C21D8/02 

FIELD: metallurgy.

SUBSTANCE: invention refers to metallurgy, particularly to production of hot rolled steel sheet. Sheet is made out of steel, containing wt %: 0.10 ≤ C ≤ 0.25, 1 ≤ Mn ≤ 3, Al ≥ 0.015, Si ≤ 1.985, Mo ≤ 0.30, Cr ≤ 1.5, S ≤ 0.015, P ≤ 0.1, Co ≤ 1.5, B ≤ 0.005, iron and unavoidable impurities - the rest. Also 1 ≤ Si + Al ≤ 2 and Cr + (3×Mo) ≥ 0.3. Microstructure of steel consists of at least 75 % of bainite, residual austenite at amount equal or exceeding 5 % and martensite at amount equal or exceeding 2 %.

EFFECT: sheet possesses tensile strength over 1200 MPa, ratio impact strength/tensile strength R_e/R_m less, than 0,75 and ultimate elongation over 10 %.

25 cl, 2 dwg, 3 tbl, 1 ex