Chromium-containing metal and manufacturing method thereof

Abstract

The high-Cr-containing metal according to the present invention is a chromium-containing metal manufactured in an arc melting furnace, and contains at least 85% Cr, up to 0.005% Al, up to 0.1% Si, and up to 0.002% S. The manufacturing method of this high-Cr-containing metal comprises the steps of reducing chromium oxides heated and melted in the arc melting furnace with Si, obtaining a molten metal containing at least 85% Cr, then, discharging slag generated in this Si reduction from the arc melting furnace, adding a basic flux into the arc melting furnace after discharging slag, melting the basic flux by electric arc, refining the molten metal by contacting the slag generated through melting of the basic flux with the molten metal, and then, tapping the molten metal from the arc melting furnace and cast.

1 - 10 . (canceled)  
   
   
       11 . A chromium-containing metal manufactured through a method comprising the steps of: 
 reducing a chromium oxide with silicon by heating and melting, in an arc melting furnace, the chromium oxide with sufficient silicon to obtain a primary slag and a molten metal containing at least 85 mass % chromium and more than 0.2 mass % and less than 1.0 mass % silicon;    then, discharging the primary slag from the arc melting furnace;    adding, after discharge of the primary slag, a basic flux into the arc melting furnace to melt the basic flux by electric arc to obtain a secondary slag;    refining the molten metal containing at least 85 mass % chromium and silicon by contacting the secondary slag with said molten metal to form a refined molten metal with a silicon content which is reduced to below 0.1 mass %:    and then, tapping the refined molten metal from the arc melting furnace and casting the refined molten metal to form cast chromium-containing metal.    
   
   
       12 . A chromium-containing metal according to  11 , wherein said basic flux mainly comprises CaO.  
   
   
       13 . A chromium-containing metal according to  claim 11 , wherein said chromium-containing metal comprising at least 85 mass % chromium, up to 0.005 mass % aluminum, up to 0.1 mass % silicon, and up to 0.002 mass % sulfur.  
   
   
       14 . A chromium-containing metal according to  13 , wherein said basic flux mainly comprises CaO.  
   
   
       15 . A chromium-containing metal, comprising at least 85 mass % chromium, up to 0.005 mass % aluminum, up to 0.1 mass % silicon, up to 0.002 mass % sulfur, and up to 0.005 mass % nitrogen, manufactured through a method comprising the steps of: 
 reducing a chromium oxide with silicon by heating and melting, in an arc melting furnace, the chromium oxide with sufficient silicon to obtain a primary slag and a molten metal containing at least 85 mass % chromium and more than 0.2 mass % and less than 1.0 mass % silicon;    then, discharging the primary slag from the arc melting furnace;    adding, after discharge of the primary slag, a basic flux into the arc melting furnace to melt the basic flux by electric arc to obtain a secondary slag;    refining the molten metal containing at least 85 mass % chromium and silicon by contacting the secondary slag with said molten metal to form a refined molten metal with a silicon content which is reduced to below 0.1 mass %;    tapping the refined molten metal from the arc melting furnace and casting the refined molten metal to form cast chromium-containing metal;    and then, the cast chromium-containing metal is crushed, and the crushed chromium-containing metal is subjected to a vacuum heating treatment.    
   
   
       16 . A chromium-containing metal according to  15 , wherein said basic flux mainly comprises CaO.  
   
   
       17 . A chromium-containing metal, comprising at least 85 mass % chromium, up to 0.005 mass % aluminum, up to 0.1 mass % silicon, up to 0.002 mass % sulfur, and up to 0.005 mass % nitrogen, manufactured through a method comprising the steps of: 
 reducing a chromium oxide with silicon by heating and melting, in an arc melting furnace, the chromium oxide with sufficient silicon to obtain a primary slag and a molten metal containing at least 85 mass % chromium and more than 0.2 mass % and less than 1.0 mass % silicon;    then, discharging the primary slag from the arc melting furnace;    adding, after discharge of the primary slag, a basic flux into the arc melting furnace to melt the basic flux by electric arc to obtain a secondary slag;    refining the molten metal containing at least 85 mass % chromium and silicon by contacting the secondary slag with said molten metal to form a refined molten metal with a silicon content which is reduced to below 0.1 mass %;    tapping the refined molten metal from the arc melting furnace and casting the refined molten metal to form cast chromium-containing metal;    the cast chromium-containing metal is crushed;    the crushed chromium-containing metal is formed into briquettes;    and then, the resultant briquettes are subjected to a vacuum heating treatment.    
   
   
       18 . A chromium-containing metal according to  17 , wherein said basic flux mainly comprises CaO.