METHOD OF PRODUCING HIGH-STRENGTH MARTENSITIC SHEET STEEL AND THERMAL STRAIN COMPLEX TO THIS END Russian patent published in 2013 - IPC C21D8/02 B21B1/22 C21D9/06 

FIELD: metallurgy.

SUBSTANCE: proposed method comprises austenitising heating of blanks, multipass rolling into sheets, sheets tempering by water to martensite and straightening by alternate bending. Note here that tempering is carries out at 900-950°C to 300-400°C at average cooling rate of, at least, 10°C/s while straightening is performed to 0.5-10%. Thermal strain complex comprises heating furnace, reversible sheet rolling mill, forehearth to heat sheets to temperature of tempering point. Note here that said forehearth is equipped with sheet temperature transducer while straightening-tempering machine incorporates sheet temperature controller.

EFFECT: higher mechanical properties and flat surface accuracy.

2 cl, 1 tbl, 1 dwg