METHOD FOR MANUFACTURING HIGH-STRENGTH STRUCTURAL STEEL AND HIGH-STRENGTH STRUCTURAL STEEL PRODUCT Russian patent published in 2017 - IPC C21D1/18 C21D8/02 C21D9/16 C22C38/02 C22C38/18 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, specifically to production of high-strength structural steel. Method of producing high-strength structural steel includes a step of making a steel slab, a heating step (1) for heating said steel slab to a temperature in range of 950 to 1,300 °C, a temperature equalising step (2) for equalising temperature of steel slab, a hot rolling step including a hot rolling stage (5) of type I for hot rolling in n-recrystallisation temperature range below recrystallisation stop temperature (RST), but above ferrite formation temperature A₃ and to provide a finish rolling temperature (FRT), a quenching step (6) for quenching hot-rolled steel at cooling rate of at least 20 °C/s to a quenching-stop temperature (QT), which quenching-stop temperature (QT) is between M_s and M_f temperatures, a partitioning treatment step (7, 9) for partitioning hot-rolled steel in order to transfer carbon from martensite to austenite, and a cooling step (8) for cooling hot-rolled steel to room temperature by forced or natural cooling.

EFFECT: obtained steel is characterised by high strength and impact viscosity.

40 cl, 9 dwg, 3 tbl