Cored wire for the metallurgical treatment of a bath of molten metal and corresponding method

Abstract

A cored wire ( 1; 100 ) intended to be injected into a molten metal bath to perform metallurgical treatment, the cored wire comprising: a fill ( 2 ) extending locally along a longitudinal axis (L), the fill comprising at least one active substance to treat the molten metal; and an outer sheath ( 4 ) extending longitudinally around the fill, characterized in that the fill comprises: an extruded bar ( 8 ) extending longitudinally and comprising the active substance; and an intermediate layer ( 10 ) extending longitudinally between the extruded bar and the outer sheath and comprising a powder containing one or more from among: a metal, a mixture of metals, a metal oxide, a mixture of metal oxides.

1 . A cored wire configured to be injected into a molten metal bath to perform metallurgical treatment, the cored wire comprising:
 a fill extending locally along a longitudinal axis, the fill comprising at least one active substance to treat the molten metal; and   an outer sheath extending longitudinally around the fill;   wherein the fill comprises:   an extruded bar extending longitudinally and comprising the active substance; and   an intermediate layer extending longitudinally between the extruded bar and the outer sheath and comprising a powder comprising one or more selected from the group consisting of: a metal, a mixture of metals, a metal oxide and a mixture of metal oxides.   
     
     
         2 . The cored wire according to  claim 1 , wherein the fill further comprises a thermally insulating layer extending longitudinally between the extruded bar and the intermediate layer. 
     
     
         3 . The cored wire according to  claim 1 , wherein the extruded bar has an equivalent outer diameter D 1  in a transverse plane substantially perpendicular to the longitudinal axis, the intermediate layer having an equivalent outer diameter D 2  in the transverse plane, with D 2  between 1.3 and 6.2 times D 1 . 
     
     
         4 . The cored wire according to  claim 1 , wherein the outer sheath comprises a strip comprising steel, aluminium, copper, nickel or zinc, or an alloy of two or more of these elements. 
     
     
         5 . The cored wire according to  claim 1 , wherein the extruded bar mostly contains magnesium. 
     
     
         6 . The cored wire according to  claim 5 , wherein the powder of the intermediate layer mostly comprises an alloy of iron and silicon, and also comprises calcium and/or barium and/or one or more rare earths. 
     
     
         7 . The cored wire according to  claim 1 , wherein the extruded bar mostly comprises calcium. 
     
     
         8 . The cored wire according to  claim 7 , wherein the powder of the intermediate layer comprises an iron powder or a mixture of iron powder and aluminium powder and/or magnesium powder and/or slag powder. 
     
     
         9 . A method for metallurgical treatment of a molten metal bath, the method comprising a step of feeding a cored wire according to  claim 1  into the molten metal bath. 
     
     
         10 . The method according to  claim 9 , wherein the molten metal is iron melt and wherein the fed cored wire is as described by  claim 5 . 
     
     
         11 . The method according to  claim 9 , wherein the molten metal is steel and wherein the fed cored wire is as described in  claim 7 .