Electrical steel sheet with layer improving electrical insulation and method for its manufacture

Abstract

The invention relates to an electrical steel sheet (11) having a layer (14) to improve electrical insulation and to a method for its production. According to the invention, the layer ( 14 ) consists of titanium oxide or tantalum oxide, wherein the interior of the electrical steel sheet ( 11 ) is adjoined by a diffusion zone ( 15 ), which is enriched with tantalum or titanium. This has the advantage that the layer adheres better to the electrical steel sheet (11). In addition, the tantalum or titanium of the diffusion zone ( 15 ) can also be used as a reservoir which causes a spontaneous passivation of damaged parts of the layer ( 14 ). Corrosion protection is thus ensured even in the event of damage to the layer ( 14 ). Furthermore, the invention relates to a method for producing electrical steel sheet in the described manner.

Description

technical field

[0001] The invention relates to an electrical steel sheet with a layer for improved electrical insulation. Background technique

[0002] According to the prior art, such electrical steel sheets are used for electric drives, for example, in the manufacture of stators. The materials used are regulated by the standard EN 10106 (since 1995). The materials mentioned in this standard result in a wide variety of product ranges, whereby the requirements of different applications can be met. The materials that can be used range from low-alloy steels with excellent magnetic permeability, good thermal conductivity and stampability to high-alloy steels with very low remagnetization losses also at higher frequencies. The standard alloy contains copper (<=0.02%), manganese (<=1.2%), silicon (0.1-4.4%), aluminum (0.1-4.4%), phosphorus (<=0.15%), zinc (<=0.2 %) and antimony (<=0.2%) as alloy components in which the sum of the silicon content and twice the a...

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