ANISOTROPIC ELECTRICAL STEEL SHEET Russian patent published in 2020 - IPC C21D8/12 C22C38/00 H01F1/16 C23C22/00 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, namely to sheet of anisotropic electrical steel used as material of iron core of transformers. Sheet of electrical steel contains steel sheet and layer of chromium-free insulating coating formed on surface of steel sheet. Between said steel sheet and layer of chromium-free insulating coating can contain forsterite layer. Chromium-free insulating coating contains metal phosphate, colloidal silica and fine particles. Colloidal silica is contained in amount of 20–150 weight parts per 100 weight parts of metal phosphate. Finely dispersed particles are one or more species selected from a group consisting of silicon carbide, silicon nitride, aluminium nitride, boron nitride, sialon and cordierite have average size of 0.3–7.0 mcm and are contained in amount of 0.5–7 pts.wt per 100 pts.wt of metal phosphate. Degree of crystallinity of metal phosphate is from 2 % to 40 %.

EFFECT: obtaining a chrome-free insulating coating having high adhesion and corrosion resistance and capable of applying a considerably greater stretching to the steel sheet, as well as high magnetic properties.

8 cl, 3 tbl