METHOD OF HIGH-STRENGTH THICK-SHEET STEEL PRODUCTION Russian patent published in 2014 - IPC C21D8/02 C22C38/50 

FIELD: metallurgy.

SUBSTANCE: invention can be used for production of 8.0-40.0 mm deep steel sheets for making of platforms for trucks operated in Far North. Slabs are made of steel containing in wt %: 0.13-0.18 C, 0.40-0.60 Si, 0.7-0.9 Mn, 1.3-1.6 Cr, 0.02-0.07 Al, 0.03-0.06 Nb, 0.01-0.06 Ti, 0.002-0.030 Ca, Ni≤0.30, Cu≤0.30, N≤0.010, Fe and impurities making the rest. Cast slabs are annealed at 640-660°C. Thereafter, they are heated and hot rolled at 1200-1260°C and 870-950°C with further quenching in water and tempering.

EFFECT: better mechanical properties and higher yield.

3 tbl