Grain Oriented Electrical Steel Flat Product Comprising an Insulation Coating

Abstract

A grain oriented electrical steel flat product includes an insulation coating layer being applied on at least one surface of the flat product, the insulating coating including a matrix containing phosphate and silica. The insulation coating layer additionally contains filler particles, said filler particles including a core consisting of a high Young's modulus material and a shell, the shell surrounding said core and consisting of a material by which the filler particles are bonded to the matrix.

1 . A grain oriented electrical steel flat product comprising an insulation coating layer being applied on at least one surface of the flat product, the insulation coating comprising a matrix containing phosphate and silica,
 wherein   the insulation coating additionally contains filler particles, said filler particles comprising
 a core consisting of a high Young's modulus material 
   and
 a shell, the shell surrounding said core and consisting of a material by which the filler particles are bonded to the matrix. 
   
     
     
         2 . The grain oriented electrical steel flat product according to  claim 1 , wherein the insulation coating layer comprises
 0.1-50.0 wt.-% filler particles.   
     
     
         3 . The grain oriented electrical steel flat product according to  claim 1 , wherein said filler particles have an average diameter of 10 to 1000 nm. 
     
     
         4 . The grain oriented electrical steel flat product according to  claim 1 , wherein the core of the filler particles comprises or consists of at least one transition metal oxide and/or metal oxide. 
     
     
         5 . The grain oriented electrical steel flat product according to  claim 1 , wherein the core of the particles is made from a material which has a Young's modulus of at least 200 GPa. 
     
     
         6 . The grain oriented electrical steel flat product according to  claim 5 , wherein the core of the particles is made from a material which has a Young's modulus of 250-650 GPa. 
     
     
         7 . The grain oriented electrical steel flat product according to  claim 1 , wherein the core of the filler particles is formed by a material, which comprises or consists of at least one transition metal oxide and/or metal oxide. 
     
     
         8 . The grain oriented electrical steel flat product according to  claim 6 , wherein the material of the core comprises or consists of Al 2 O 3 , TiO 2  and/or ZrO 2 . 
     
     
         9 . The grain oriented electrical steel flat product according to  claim 1 , wherein the shell of the filler particles is formed by an inorganic material. 
     
     
         10 . The grain oriented electrical steel flat product according to  claim 1 , wherein the shell of the filler particles comprises or consists of aluminum oxide, aluminum hydroxide and/or silica. 
     
     
         11 . The grain oriented electrical steel flat product according to  claim 1 , wherein the core material of the filler particles makes up 80.0-99.9% by weight of the filler particles. 
     
     
         12 . The grain oriented electrical steel flat product according to  claim 1 , wherein the concentration of filler particles in the insulating layer is from 0.1-50.0 wt.-%. 
     
     
         13 . The grain oriented electrical steel flat product according to  claim 1 , wherein the phosphate component of the matrix of the insulating layer is in the form of at least one metal phosphate. 
     
     
         14 . The grain oriented electrical steel flat product according to  claim 1 , wherein the silica component of the matrix of the insulating layer is colloidal silica. 
     
     
         15 . The grain oriented electrical steel flat product according to  claim 1 , wherein the insulation layer is free of chromium compounds.