Billet, method of working a billet, and ferrous product produced from a billet

Abstract

A billet includes a solid steel body and an alloy cladding. The cladding may include a square tube in which the body is inserted with an interface at which the cladding becomes bonded to the body when the billet is heated and rolled or otherwise worked into a ferrous product. At least one element composed of a mass of finely divided scavenging aluminium, titanium or magnesium, is placed in the tube adjacent the body and separate from the interface. The elements are advantageously compressed into briquettes which scavenge oxygen from residual air at the interface to prevent oxidation of the cladding at the interface. The tube may be closed to prevent gases outside the billet from penetrating to the interface. Alternatively, reliance may be placed on the briquettes to scavenge oxygen from the residual air and also from atmospheric air and furnace gases before they can penetrate to the interface.

1 . A billet comprising:
 a solid steel body;   a cladding member at least a portion of which is comprised of an alloy selected from the group consisting of stainless steel, nickel-chrome, nickel-copper and copper-nickel alloys; and   scavenging metal located in a position that is separate from an interface between at least a portion of the steel body and said portion of the cladding member;   
       the billet being configured so that, upon being sealed, evacuated and heated, the billet is adapted to be worked to form a ferrous product in which said portion of the solid steel body and said portion of the cladding member are bonded together at the interface. 
     
     
         2 . The billet according to  claim 1 , wherein the cladding member forms at least a part of a sealed housing in which the solid steel body and the scavenging metal are enclosed. 
     
     
         3 . The billet according to  claim 1 , wherein the scavenging metal is selected from the group consisting of aluminum, titanium, magnesium and an alloy of magnesium and aluminum. 
     
     
         4 . The billet according to  claim 1 , wherein the scavenging metal comprises a first portion comprised of aluminum, magnesium or an alloy thereof and a second portion comprised of titanium. 
     
     
         5 . The billet according to  claim 1 , wherein the scavenging metal is located adjacent at least one end of the solid steel body. 
     
     
         6 . The billet according to  claim 1 , wherein the billet is configured so that the scavenging metal scavenges oxidizing gases that evolve in the billet when the billet is heated. 
     
     
         7 . The billet according to  claim 1 , wherein the alloy of which the cladding member is composed is stainless steel. 
     
     
         8 . The billet according to  claim 2 , wherein the housing is comprised of a first part in which the body is located, and a second part in which the mass of scavenging metal is inserted before the two parts are joined together. 
     
     
         9 . The billet according to  claim 2 , wherein the scavenging metal is selected from the group consisting of aluminum, titanium, magnesium and an alloy of magnesium and aluminum. 
     
     
         10 . The billet according to  claim 2 , wherein the scavenging metal is located adjacent at least one end of the solid steel body. 
     
     
         11 . The billet according to  claim 2 , wherein the billet is configured so that the scavenging metal scavenges oxidizing gases that evolve in the billet when the billet is heated. 
     
     
         12 . The billet according to  claim 1 , wherein the cladding member is comprised of at least two parts which are joined together to form a sealed housing in which the solid steel body and the scavenging metal are enclosed. 
     
     
         13 . The billet according to  claim 1 , wherein, upon heating, the scavenging metal scavenges nitrogen initially present in the billet before the billet is worked. 
     
     
         14 . A ferrous product produced by heating and working a billet as claimed in  claim 1 . 
     
     
         15 . A ferrous product produced by heating and working a billet as claimed in  claim 2 . 
     
     
         16 . A method of working a billet comprising:
 a solid steel body;   a cladding member at least a portion of which is comprised of an alloy selected from the group consisting of stainless steel, nickel-chrome, nickel-copper and copper-nickel alloys, and   scavenging metal located in a position that is separate from an interface between at least a portion of the steel body and said portion of the cladding member;   
       the method including the steps of evacuating the billet, sealing the billet, heating the billet and working the billet to form a ferrous product in which said portion of the solid steel body and said portion of the cladding member are bonded together at the interface. 
     
     
         17 . The method according to  claim 16 , wherein the cladding member forms at least a part of a sealed housing in which the solid steel body and the scavenging metal are enclosed. 
     
     
         18 . The method according to  claim 16 , wherein the scavenging metal is selected from the group consisting of aluminum, titanium, magnesium and an alloy of magnesium and aluminum. 
     
     
         19 . The method according to  claim 16 , wherein the scavenging metal comprises a first portion comprised of aluminum, magnesium or an alloy thereof and a second portion comprised of titanium. 
     
     
         20 . The method according to  claim 16 , wherein the billet is configured so that the scavenging metal scavenges oxidizing gases that evolve in the billet when the billet is heated. 
     
     
         21 . The method according to  claim 17 , wherein the billet is configured so that the scavenging metal scavenges oxidizing gases that evolve in the billet when the billet is heated. 
     
     
         22 . The method according to  claim 16 , wherein the scavenging metal is located adjacent at least one end of the solid steel body. 
     
     
         23 . The method according to  claim 16 , wherein the cladding member is comprised of at least two parts which are joined together to form a sealed housing in which the solid steel body and the scavenging metal are enclosed. 
     
     
         24 . The method according to  claim 16 , wherein, upon being heated, the scavenging metal scavenges nitrogen initially present in the billet before the billet is worked. 
     
     
         25 . A ferrous product produced by a method as claimed in  claim 16 .