PRODUCTION METHOD OF COLD-ROLLED ISOTROPIC ELECTRIC STEEL Russian patent published in 2009 - IPC C21D8/12 

FIELD: metallurgy.

SUBSTANCE: invention relates to ferrous metallurgy field. For increasing of steel magnetic properties level it is received strip made from isotropic, containing silicon non more than 2 wt %, aluminium 0.1-0.5 wt %, carbon 0.015-0.065 wt %, it is subject to double-ply cold rolling with the total deformation ratio at the second cold rolling non more than 4.8%, decarburising annealing and finishing heat processing. The second strip cold strain is implemented by tension with rolling strain 20-60 tonne, decarburising annealing is implemented with 790-850°C, finishing heat processing is implemented with double-stage heating, while at the first stage it is heated till 810-870°C, at the second stage - till 940-980°C, and heating from the first to the second stage is implemented at a rate of 120-180°C/min. Heating from the first to the second stage of finishing heat processing is implemented at a rate, defining depending on aluminium content in a steel: V_1-2=150×[Al]+210, °C/min. Finishing heat processing at the second stage is implemented at the temperature T_{2 stage}=60×[Si]+860, °C.

EFFECT: increasing of steel magnetic properties level.

3 cl, 3 ex, 1 tbl