METHOD FOR PRODUCING COLD-ROLLED STEEL WITH INCREASED CORROSION RESISTANCE Russian patent published in 2024 - IPC C21D8/04 C22C38/02 C22C38/04 C22C38/06 C22C38/08 C22C38/16 

FIELD: metallurgy.

SUBSTANCE: methods for the production of cold-rolled steels that can be used for the manufacture of stamped products. The method includes steel smelting, casting, hot rolling on a continuous broadband mill to produce hot-rolled strips, winding of strips into rolls, cold rolling to produce cold-rolled strips, full annealing and temper rolling. Smelted steel contains, wt.%: carbon 0.01-0.10, silicon 0.01-0.03, manganese 0.15-0.40, phosphorus 0.005-0.018, sulfur 0.005-0.020, aluminum 0.03 -0.05, nickel 0.04-0.07, copper 0.04-0.12, iron and inevitable impurities the rest. Hot rolling is completed at a temperature of 880-920°C. Winding of hot-rolled strips into rolls is carried out at a temperature of 630-750°C. Full annealing of cold-rolled strip is carried out in a continuous annealing unit (CAU) at a temperature of 800-850°C, while the speed of movement of the cold-rolled strip is 100-230 m/min, and the heating temperature in the CAU at the initial stages of recrystallization P2 is 620-670°C.

EFFECT: it is ensured that steel is produced with a corrosion rate of no more than 0.17 mm/year and the required level of strength and plastic properties for cold stamping, excluding the formation of surface defects.

1 cl, 2 tbl