HIGH STRENGTH STEEL PLATE AND HIGH STRENGTH GALVANISED STEEL PLATE WITH GOOD FORMABILITY, AND METHODS OF THEIR MANUFACTURING Russian patent published in 2015 - IPC C22C38/06 C22C38/04 C21D8/02 C23C2/02 C23C2/40 

FIELD: metallurgy.

SUBSTANCE: plate is made from steel containing in wt %: C: 0.075 - 0.30, Si: 0.70-2.50, Mn: 1.30-3.50, P: 0.001-0.03, S: 0,0001-0,01, Al: 0.005-1.50, N: 0.0001-0.01, O: 0.0001-0.01, and as optional elements one or more elements from: Ti: 0.005-0.15, Nb: 0.005-0.15, B: 0.0001-0.010, Cr: 0.01-2.0, Ni: 0.01-2.0, Cu: 0.01-2.0, Mo: 0.01-1.0, V: 0.005-0.15 and one or more from Ca, Ce, Mg, Zr, Hf and REM: in total 0.0001-0.5, at that iron and inevitable admixtures - rest. Plate microstructure contains phase of residual austenite in amount of 1-20 vol %, with martensitic transformations point -60°C or below.

EFFECT: plate has high formability during storage, maximum tension strength 900 MPa or over, and high viscosity and suitability for flanging-rolling-out.

11 cl, 3 dwg, 26 tbl, 1 ex