METHOD OF PRODUCING ULTRAHIGH-STRENGTH SHEET STEEL Russian patent published in 2016 - IPC C21D8/02 C21D9/42 C22C38/54 F41H5/02 

FIELD: metallurgy.

SUBSTANCE: to provide high strength properties of sheets at maintaining sufficient ductility and impact viscosity of method involves production of continuously cast slab, heating, hot rolling, hardening and tempering sheets, continuously cast slab is made from steel of following chemical composition, wt%: 0.40-0.47 C; 0.20-0.50 Si; 0.50-0.90 Mn; 0.40-0.80 Cr; 1.80-2.30 Ni; 0.30-0.50 Mo; 0.02-0.06 V; 0.02-0.08 Al; 0.001-0.010 N; 0.10-0.20 Cu; 0.002-0.020 Nb; 0.002-0.015 Ti; 0.001-0.005 B; not more than 0.005 S; not more than 0.010 P; Fe the rest, tempering is performed at temperature of 930-980°C, tempering at temperature of 170-200°C.

EFFECT: production of a new highly efficient type of metal - rolled plates of ultra-high strength low-alloy steel bulletproof protection for vehicle body.

1 cl, 3 tbl, 1 ex