TEXTURIZED SILICON STEEL AND METHOD OF ITS MANUFACTURE Russian patent published in 2017 - IPC C21D8/12 C22C38/02 

FIELD: metallurgical engineering.

SUBSTANCE: slab of silicon steel containing 2.5-4.0 wt % Si and as inhibitor elements 0.010-0.040 wt % of an acid soluble aluminium Al_s, 0.004-0.012 wt % N and 0.015 wt % or less S, the rest C, Mn, Fe and unavoidable impurities are heated to the temperature of 1100-1200 °C followed by hot rolling to form a hot-rolled sheet. The hot-rolled sheet is annealed at a temperature of 900-1150 °C and the cooling rate during annealing 20-100 °C/sec. The cold rolling of hot rolled sheet is performed with a reduction ratio of 85% or higher to obtain a cold rolled sheet of a finite thickness. The cold-rolled sheet is annealed to obtain a texturized sheet of textured silicon steel, in which the proportion of the area of small crystalline grains having a size of less than 5 mm does not exceed 3%, and the ratio μ17/15μ of magnetic permeability with a magnetic induction of 1.7 T to a magnetic permeability with a magnetic induction of 1.5 T is 0.50 or higher. The cold-rolled sheet annealing includes the following sequential operations: decarburization annealing, application of coating from the annealing separator, nitriding treatment, high-temperature annealing, application of insulating coating and hot-stretching annealing.

EFFECT: obtaining sheets of texturized silicon steel with excellent magnetic properties.

6 cl, 3 tbl, 31 ex