FIELD: metallurgy.
SUBSTANCE: invention relates to the field of metallurgy and namely to a textured sheet of electrical steel used as material for iron cores for transformers. The steel has a chemical composition containing, in wt%: Si - 1.5 to 8.0, Mn - 0.02 to 1.0, C - 50 ppm or less, at least one element selected from the group consisting of Sn: from 0.010 to 0.400, Sb: from 0.010 to 0.400, Mo: from 0.010 to 0.200 and P: from 0.010 to 0.200, the balance is Fe and inevitable impurities. The crystalline grains of the sheet include large grains of secondary recrystallization characterized by an average grain size of 5 mm or more and fine grains characterized by a grain size in the range from 0.1 mm to 2.0 mm. At least some of the coarse secondary recrystallization grains penetrate the steel sheet in the thickness direction and, respectively, protrude on the front and rear surfaces of the steel sheet in such a way so that the projection planes for the protruding surfaces of these coarse secondary recrystallization grains on the front and rear surfaces at least partially overlap each other forming an overlap area. The aspect ratio between the surface area for the overlap area and the average surface area of the protruding surfaces is 80% or more, and fine grains are present at number density per unit of the surface area in the range from 0.6 pcs/cm2 to 40 pcs/cm2.
EFFECT: invention provides excellent high frequency core loss performance and machinability when cutting a blank.
3 cl, 3 tbl, 2 ex, 4 dwg
