ANISOTROPIC ELECTRICAL STEEL SHEET Russian patent published in 2024 - IPC C23C22/00 C21D8/12 C22C38/00 H01F1/14 H01F1/18 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, namely to sheet of anisotropic electrical steel used as material of iron cores of transformers. Anisotropic electrical steel sheet comprises a main steel sheet, an intermediate layer located on the main steel sheet and in contact with it, and an insulating coating located on the intermediate layer and in contact with it. Intermediate layer is an oxide film having an average thickness of 2–500 nm and satisfying the following conditions: Si content: 20–70 at.%, O content: 30–80 at.%, Mg content: 20 at.% or less, content of P: 5 at.% or less and Fe content: less than 20 at.%. Insulating coating is a phosphate coating having an average thickness of 0.1–10 mcm and satisfying the following conditions: P content: 5–30 at.%, Si content: 5–30 at.%, O content: 30–80 at.%, Al content: 0.1–10 at.%, Cr content: less than 1 at.%, Fe content: less than 25 at.%, Mg content: 0–10 at.%, Mn content: 0–10 at.%, Ni content: 0–10 at.%, Zn content: 0–10 at.%, V content: 0–10 at.%, W content: 0–10 at.%, Zr content: 0–10 at.%, Co content: 0–10 at.%, and Mo content: 0–10 at.%. X-ray diffraction at grazing incidence carried out on a phosphate coating using a Co-Kα excitation source, X-ray diffraction pattern has a diffraction peak originating from a cristobalite-type aluminium phosphate, at a diffraction angle of 2θ=24.8°. When the half-width of the diffraction peak under diffraction conditions, where the angle of incidence of X-rays ω=0.5°, is denoted as FWHM_0.5, and half-width of diffraction peak in diffraction conditions, where the angle of incidence of X-rays ω=1.0°, denoted as FWHM_1.0, FWHM_0.5 and FWHM_1.0 satisfy the following conditions: 0.20° ≤ FWHM_0.5 ≤ 2.00°, 0.20° ≤ FWHM_1.0 ≤ 2.00° and 0° ≤ |FWHM_0.5-FWHM_1.0| ≤ 1.00°.

EFFECT: sheet has excellent adhesion of insulating coating.

1 cl, 3 dwg, 7 tbl