abstract |
FIELD: metallurgy.SUBSTANCE: invention relates to metallurgy, namely to textured electrical steel sheet used as material of iron core for low-noise transformers. Steel surface is coated with insulating film with chemical composition containing Si, P, O and at least one element selected from Mg, Ca, Ba, Sr, Zn, Al, Mn and Co. Insulating film has degree of crystallinity equal to 20 % or more. Minimum tension applied to sheet steel by insulating film at temperature in range from 100 °C to 200 °C is 10 MPa or more, and static friction coefficient of insulating film makes 0.21 to 0.50.EFFECT: reduced level of transformer noise.7 cl, 3 tbl, 3 ex |