TEXTURED ELECTRICAL STEEL SHEET AND METHOD OF ITS PRODUCTION Russian patent published in 2020 - IPC C22C38/60 C21D8/12 H01F1/16 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, namely to textured electrical steel sheet used as material of iron cores of large-sized transformers. Steel contains the following chemical composition, wt%: C: not more than 0.005, Si: 2.5–6.0, Mn: 0.01–0.80, S: not more than 0.005, Se: not more than 0.005, N: not more than 0.005, rest is Fe and unavoidable impurities, and also provided on its surface with forsterite film, formed mainly from forsterite. Average length L in the rolling direction for crystalline grains having a size in the sheet thickness direction corresponding to the said thickness is no more than 25 mm. Relative amount P of crystalline grains having a length in the rolling direction of not more than 5 mm relative to all crystalline grains is within range of 40 to 90 %. Degree of presence of sulphides of at least one alkali-earth metal selected from Ca, Sr and Ba, with diameter of equivalent circle making at least 0.5 mcm, when observing cross-section of forsterite film in direction of sheet width is not more than 0.2/mcm per unit length in direction of sheet width.

EFFECT: low losses in the core are provided with low variation thereof.

5 cl, 5 dwg, 4 tbl, 3 ex