METHOD OF PRODUCTION OF THE STEEL STRIPS (VERSIONS) Russian patent published in 2006 - IPC C21D8/04 C21D9/48 

FIELD: ferrous metallurgy; methods of production of the steel strips.

SUBSTANCE: the invention is pertaining to the field of ferrous metallurgy, in particular, to the method of production of the steel strips from the low-carbon automobile-body sheet steel. The technical result of the invention is the increased output the steel strips: the rather special complex ironing (RSCI), the special complex ironing (SCI), the complex ironing (CI) and ensuring achievement of the required level of the physical-mechanical properties of the steel strips. The technical problem has been solved in three versions. The steel strip is produced by the hot rolling, the subsequent cold rolling, the reeling of the cold-rolled strips in the rolls and their annealing in the bell-type furnaces with the heating up to the temperatures of the recrystallization annealing below_{ACl : 650-720°C. The RSCI rolls heating exercise in four stages: on the first stage - up to 320-600°C with the rate of 60-270°C/h, on the second stage - up to 360-630°C with the rate of 10-30°C/h, on the third stage - up to 400-649°C with the rate of 5-7°C/h, on the fourth stage - up to 650-720°C with rate of 8-70°C/h. In the second version SCI rolls are heated up in three stages: on the first stage - up to 320-600°C with the rate of 60-270°C/h, on the second stage - up to 360-649°C with the rate of 10-30°C/h, on the third stage - up to 650-720°C with the rate of 8-70°C/h. In the third version the CI rolls are heated up to 650-720°C in two stages: on the first stage - up to 320-649°C with the rate of 60-270°C/h, on the second stage - up to 650-720°C with the rate of 8-70°C/h.}

EFFECT: the invention ensures the achievement of the required level of the physical-mechanical properties of the steel strips.

3 cl, 3 tbl, 5 ex