METHOD FOR PRODUCTION OF HIGH-STRENGTH STEEL SHEET Russian patent published in 2016 - IPC C21D8/02 C22C38/58 C22C38/50 

FIELD: metallurgy.

SUBSTANCE: invention relates to ferrous metallurgy, particularly, to production of rolled plates from high-strength alloyed steel intended for crane production and light transport equipment. Obtained is a continuously cast slab from steel of the following chemical composition, wt%: 0.07-0.12 C, 0.05-0.30 Si, 1.1-1.7 Mn, 0.30-0.70 Cr, 0.90-1.20 Ni, 0.20-0.40 Mo, 0.03-0.07 V, 0.02-0.05 Al, from more than 0.006 to 0.010 N, 0.05-0.25 Cu, 0.02-0.09 Nb, from 0.003 to below 0.005 of Ti, not more than 0.005 of S, not more than 0.015 of P, Fe - the rest. To upgrade hardenability the composition of steel is additionally introduced with boron 0.001-0.005 wt%. Slab is heated, hot rolled to produce sheets, they are hardened and tempered. Hardening is carried out at the temperature of 930-980 °C, and tempering at the temperature of 500-600 °C.

EFFECT: provided are high strength properties of the sheets at maintaining sufficient ductility and impact strength.

1 cl, 4 tbl