Patent ID: 8871035

Claim:
A process for the production of grain oriented magnetic sheets, wherein a slab made of steel having a thickness of ≦100 mm, containing Si in the range comprised between 2.5 and 3.5% by weight, is subjected to a thermomechanical cycle consisting of the following operations: optional first heating, to a temperature T1 no higher than 1250° C. first rough hot-rolling, in a first rough hot rolling mill, at a temperature T2 between 900 and 1200° C., the reduction ratio (% Rid) applied to the first rough hot-rolling being adjusted so as to be of at least 80%, in the absence of a subsequent heating to a temperature T3 of at least 60% determined by the following relationship % ⁢ ⁢ Rid = 80 - ( T ⁢ ⁢ 3 - T ⁢ ⁢ 2 ) 5 in the presence of a subsequent heating to a temperature T3 lower than 1300° C., optional second heating, to a temperature T3>T2 second finishing hot-rolling, in a second finishing hot rolling mill, at a temperature T4<1300° C., to a thickness of the rolled section in the range of 1.5 mm-3.0 mm, cold-rolling, in one or more stages, with optional intermediate annealing, wherein in the last stage a cold reduction ratio no lower than 60% is applied primary recrystallisation annealing, optionally in a decarburizing atmosphere secondary recrystallisation annealing.