METHOD OF PRODUCTION OF COLD-ROLLED STRIP MADE FROM LOW-CARBON STEEL Russian patent published in 2007 - IPC C21D8/04 

FIELD: metallurgy; production of cold-rolled strips made from low-carbon nonaging steel stabilized with aluminum which possesses high drawing properties for cold stamping of car parts.

SUBSTANCE: strip rolls are subjected to re-crystallization annealing by heating them first to intermediate temperature at rate of 60-160^°C/h; then they are heated at rate of 7-9^°C/h to temperature of 570-630^°C; final heating is carried out at rate of 30-50^°C/h; holding time at annealing temperature ranges from 12 to 18 h. Then, rolls are cooled to temperature of 680-695^°C at rate of 10-50^°C/h and cooling procedure is completed at arbitrary rate; cold rolling which is previous relative to annealing is performed at total cogging of 70-86%. Besides that, low-carbon steel has the following chemical composition, mass-%: 0.020-0.050 of C; 0.08-0.28 of Mn; Si£0.020; 0.01-0.06 of Al; N£0.01; the remainder being Fe and unavoidable admixtures.

EFFECT: improved quality of good-to-bad yield of cold-rolled strips.

4 cl, 4 tbl, 1 ex