Magnetic steel sheet having a layer improving the electrical insulation and method for the production thereof

Patent metadata

Field	Value
Publication number	US-2016125986-A1
Application number	US-201414890343-A
Country	US
Kind code	A1
Filing date	Apr 17, 2014
Priority date	May 10, 2013
Publication date	May 5, 2016
Grant date	—

Abstract

A magnetic steel sheet including a layer adjoining at least one of a top side and bottom side of the magnetic metal sheet. The layer includes a metal oxide containing titanium oxide or tantalum oxide and the layer adjoins the magnetic steel sheet along a diffusion zone into which the titanium or tantalum of the metal oxide has diffused into the magnetic steel sheet. The diffusion zone is produced on at least one of a top surface and a bottom surface of the magnetic steel sheet and the diffusion layer diffuses one of tantalum and titanium as metal into the at least one surface. The metal of the at the at least one surface is converted into an associated metal oxide to form the layer including the metal oxide, and a residual content of the metal of the metal oxide remains in the diffusion zone.

First claim

1 - 8 . (canceled)

9 . A magnetic steel sheet, comprising:
a layer adjoining at least one of a top side and a bottom side of the magnetic metal sheet, the layer including a metal oxide selected from the group consisting of titanium oxide and tantalum oxide, the layer adjoining the magnetic steel sheet along a diffusion zone into which at least one of titanium and tantalum has diffused.

10 . The magnetic steel sheet as claimed in claim 9 , wherein the layer has a thickness of between 5 μm and 10 μm inclusive.

11 . The magnetic steel sheet as claimed in claim 9 , wherein the diffusion zone includes one of a titanium content and a tantalum content of more than fifty percent by weight within a distance of 2 μm from an interface with the layer.

12 . A method for treating a magnetic steel sheet, comprising:
producing a diffusion zone on at least one of a top surface and a bottom surface of the magnetic steel sheet, the diffusion layer diffusing a metal selected from the group consisting of tantalum and titanium into the at least one surface; and converting the metal at the at least one surface into an associated metal oxide to form a layer including the metal oxide, a residual content of the metal of the metal oxide remaining in the diffusion zone.

13 . The method as claimed in claim 12 , wherein before formation of the layer, the diffusion zone has one of a titanium content and a tantalum content of more than fifty percent by weight within a distance of 5 μm from an interface with the layer.

14 . The method as claimed in claim 12 ,
wherein said producing of the diffusion zone includes a physical vapor deposition process, and wherein said converting of the metal includes heat treatment subsequent to the physical vapor deposition process.

15 . The method as claimed in claim 12 , further comprising removing a spontaneously formed passivation layer before said converting of the metal at the at least one surface into the associated metal oxide to form the layer including the metal oxide.

16 . The method as claimed in claim 12 , wherein said converting of the metal at the at least one surface into the associated metal oxide to form the layer including the metal oxide is performed as a heat treatment in an oxygen-containing atmosphere.

Assignees

• Siemens Ag

Inventors

• Jensen Jens Dahl
• Möhle Axel
• Reiche Ralph
• Schneider Manuela
• Stier Oliver

Classifications

• C21D1/74

  Methods of treatment in inert gas, controlled atmosphere, vacuum or pulverulent material · CPC title

• C23C8/02

  Pretreatment of the material to be coated (C23C8/04 takes precedence) · CPC title

• H01F1/18 Primary

  with insulating coating · CPC title

• C21D9/46

  for sheet metals · CPC title

• C23C8/10

  Oxidising · CPC title