MICRO-ALLOYED HIGH-STRENGTH MULTI-PHASE STEEL CONTAINING SILICON WITH MINIMUM TENSILE STRENGTH OF 750 MPA IMPROVED PROPERTIES AND METHOD FOR PRODUCING A STRIP FROM SAID STEEL Russian patent published in 2018 - IPC C22C38/38 C22C38/32 C21D9/46 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, namely to a high-strength multi-phase steel meant for producing a cold- or hot-rolled strip used to manufacture a lightweight vehicle construction. Steel consists of the following elements, wt.%: C from ≥ 0.075 to ≤ 0.105; Si from ≥ 0.600 to ≤ 0.800; Mn from ≥ 1.000 to ≤ 1.900; Cr from ≥ 0.100 to ≤ 0.700; Al from ≥ 0.010 to ≤ 0.060; N from ≥ 0.0020 to ≤ 0.0120; S ≤ 0.0030; Nb from ≥ 0.005 to ≤ 0.050; Ti from ≥ 0.005 to ≤ 0.050; B from ≥ 0.0005 to ≤ 0.0040; Mo ≤ 0.200; Cu ≤ 0.040; Ni ≤ 0.040; rest – iron and contamination resulting from smelting.

EFFECT: minimum tensile strength of 750 MPa, yield strength to strength ratios of up to 73 % and improved deformation properties are provided.

42 cl, 6 dwg, 8 ex