MULTI-LAYER ELECTRICAL STEEL SHEET Russian patent published in 2021 - IPC C22C38/14 C21D8/12 B32B15/01 

FIELD: metallurgy.

SUBSTANCE: invention relates to the field of metallurgy, namely to a 0.03-0.3 mm multilayer sheet of electrical steel, used for manufacturing cores of various types of electric equipment. The multilayer sheet contains an inner layer and surface layers located on both sides of the inner layer. Each of the surface layers has a chemical composition containing, wt%: C: 0.001-0.01, Si: 2.5-6.0, Ti: 0-0.005, the rest is Fe and inevitable impurities. The inner layer has a chemical composition containing, wt%: C: 0.001-0.01, Si: 1.5-5.0, Ti: 0-0.005, the rest is Fe and inevitable impurities. The multilayer electrical steel sheet has an ΔSi of 0.5 mass% or more, where ∆Si is defined as the difference between the Si content in each of the surface layers [Si]₁ and the Si content in the inner layer [Si]₀, expressed as [Si]₁- [Si]₀, and Δλ_1.0/400 equal to 1,0×10^-6 or less, where Δλ_1.0/400 is defined as the absolute value of the difference between the magnetostriction of λ_1.0/400.1 of each of the surface layers and magnetostriction of λ_1.0/400.0 of the inner layer. The ratio of the total thickness of the surface layers t₁ to t is 0.10-0.70.

EFFECT: the sheet has low high frequency iron loss and high magnetic flux density.

3 cl, 5 dwg, 2 tbl