HIGH-STRENGTH MULTI-PHASE STEEL AND METHOD FOR STRIP MANUFACTURE FROM THIS STEEL WITH MINIMUM TENSILE STRENGTH AT 580 MPa Russian patent published in 2017 - IPC C22C38/38 C22C38/18 C21D8/02 C21D9/46 C23C2/06 

FIELD: metallurgy.

SUBSTANCE: invention relates to the high-strength multi-phase steel with the minimum tensile strength 580 MPa, preferably with two-phase structure, to manufacture the cold-rolled or hot-rolled steel strip with thickness 0.50-4.00 mm with improved moulding properties, used, in particular, for automotive industry with the lightweight structures use. Steel consists of elements, wt %: C from 0.075 to ≤0.105, Si from 0.600 to ≤0.800, Mn from 1.000 to ≤2.250, Cr from 0.280 to ≤0.480, Al from 0.010 to ≤0.060, P ≤0.020, N ≤0.0100, S ≤0.0150, the rest - iron, due to the impurity melting. With the strips thickness up to 1 mm the content of Mn is preferably ≤1.500%, with the strips thickness from 1 mm up to 2 mm, the content of Mn is preferably ≤1.750%, and with the strips thickness ≥2 mm, the Mn content is preferably ≥1.500%.

EFFECT: uniform mechanical and technological strips properties and its suitability for the hot-dip galvanizing.

17 cl, 8 dwg, 4 ex