METHOD OF HEAT TREATMENT OF COLD-ROLLED STEEL TAPE OF 0,30-1,5 mm FROM STRUCTURE STEEL WITH A TENSILE STRENGTH OF 800-1,200 MPa Russian patent published in 2019 - IPC C21D1/20 C21D8/02 C21D9/52 C22C38/00 

FIELD: metallurgy.

SUBSTANCE: invention relates to heat treatment of structural steels. In order to ensure the tensile strength of 800–1,200 MPa and an elongation of at least 7.0 % in a wide range of thicknesses (0.30–1.50 mm) under conditions of a high-performance patenting unit, a cold-rolled steel tape of 0.30–1.50 mm, comprising, wt%: 0.14–0.70 of carbon, 0.15–0.60 of silicon and 0.40–1.60 of manganese, is heated at a speed of 8.0–18.0 °C/s to a holding temperature, depending on the level of alloying of steel and being determined from the expression: T_h=(990–178⋅E_ch)±10, where T_h – estimated temperature of heating the tape for patenting, °C, E_ch – equivalent of chemical composition, determined from the expression: E_ch=C+Mn/21-Si/4, where C, Mn, Si is carbon, manganese, silicon, wt%, in an atmosphere containing 0.5–2.4 % of CO, is maintained at a given temperature for 20–35 s; isothermal quenching in a lead melt is performed for 20–50 s at a temperature of 440–500 °C.

EFFECT: invention can be used in the production of high-strength packaging tape used in the metallurgical, woodworking and other industries.

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