High-purity ferroboron, a mother alloy for iron-base amorphous alloy, an iron-base amorphous alloy, and methods for producing the same

Abstract

The present invention provides methods for: producing high-purity ferroboron by using inexpensive mass-produced steel as a base iron; and producing a mother alloy for an iron-base amorphous alloy and an iron-base amorphous alloy, the alloys having excellent properties, by using the ferroboron thus produced as a raw material. The methods include: a method for producing high-purity ferroboron by using mass-produced steel obtained through a converter, an electric furnace or the like and having an Al content of 0.03 mass % or less as a base iron; a method for producing a mother alloy by adjusting the chemical composition thereof by adding a diluent base iron and auxiliary materials to the produced ferroboron; and a method for producing an iron-base amorphous alloy by preferably using mass-produced steel obtained through a converter or an electric furnace and having an Al content of 0.006 mass % or less as a diluent base iron and by casting the molten metal of the produced mother alloy through a rapid-cooling solidification process. Further, by the present invention, it is possible to economically produce an iron-base amorphous alloy thin strip for an iron core having excellent magnetic properties including a high magnetic flux density and a low core loss by using mass-produced steel having an adequate Al content as both a base iron for ferroboron and a diluent base iron for a mother alloy.

1 . A method for producing high-purity ferroboron by charging a boron source, a base iron and a carbon-base reducing agent into a melting-and-reducing furnace, characterized in that: the base iron is a steel produced using a refining furnace; and the Al content in said steel is 0.03 mass % or less.  
     
     
         2 . A method for producing high-purity ferroboron according to  claim 1 , characterized in that said melting-and-reducing furnace is an electric furnace.  
     
     
         3 . A method for producing a raw material for an iron-base amorphous alloy, characterized by adding a diluent base iron and auxiliary materials to high-purity ferroboron produced by a method according to  claim 1  or  2 .  
     
     
         4 . A method for producing a raw material for an iron-base amorphous alloy according to  claim 3 , characterized in that: said diluent base iron is a steel produced using a refining furnace; and the Al content in said steel is 0.006 mass % or less.  
     
     
         5 . A method for producing an iron-base amorphous alloy, characterized in that said iron-base amorphous alloy is produced by rapidly cooling and solidifying molten metal of a raw material for an iron-base amorphous alloy, the raw material being produced by a method according to  claim 3  or  4 .  
     
     
         6 . High-purity ferroboron characterized by containing 
 P: 0.02 mass % or more and    Al: 0.03 mass % or less,    with the balance consisting of Fe, B and unavoidable impurities.    
     
     
         7 . High-purity ferroboron according to  claim 6 , characterized by containing Ti of 0.03 mass % or less.  
     
     
         8 . A method for producing high-purity ferroboron by charging a boron source, a base iron and a carbon-base reducing agent into a melting-and-reducing furnace, characterized in that: the base iron is a steel produced using a refining furnace; and said steel is that containing P of 0.02 mass % or more and Al of 0.03 mass % or less.  
     
     
         9 . A method for producing high-purity ferroboron according to  claim 8 , characterized in that the steel contains Ti of 0.03 mass % or less.  
     
     
         10 . A method for producing high-purity ferroboron, characterized in that the molten metal of ferroboron is decarburized by blowing oxygen gas through it while the temperature, of the molten metal is 1,600° C. or higher after a production of the molten metal of ferroboron by melting-and-reducing furnace.  
     
     
         11 . A method for producing high-purity ferroboron according to  claim 10 , characterized in that said molten metal is that obtained by charging a boron source, a base iron and a carbon-base reducing agent into an electric furnace and then melting and reducing them.  
     
     
         12 . A method for producing high-purity ferroboron according to  claim 10 , characterized in that said molten metal is that obtained by remelting the ferroboron solidified after a boron source, a base iron and a carbon-base reducing agent are charged in an electric furnace and then they are melt and reduced.  
     
     
         13 . A method for producing high-purity ferroboron according to  claim 11  or  12 , characterized in that the B content in said molten metal is 10 mass % or less.  
     
     
         14 . A method for producing high-purity ferroboron according to any one of  claims 11  to  13 , characterized in that: said base iron is a steel produced using a refining furnace; and the Al content in said steel is 0.03 mass % or less.  
     
     
         15 . A method for producing a raw material for an iron-base amorphous alloy, characterized by adding a diluent base iron and auxiliary materials to high-purity ferroboron produced by a method according to any one of  claims 10  to  14  and adjusting the chemical composition thereof.  
     
     
         16 . A method for producing a raw material for an iron-base amorphous alloy according to  claim 15 , characterized in that: said diluent base iron is a steel produced using a refining furnace; and the Al content in said steel is 0.006 mass % or less.  
     
     
         17 . A method for producing an iron-base amorphous alloy, characterized in that said iron-base amorphous alloy is cast by rapidly cooling and solidifying molten metal of a raw material for an iron-base amorphous alloy, the raw material being produced by a method according to  claim 15  or  16 .