Titanium or titanium alloy contacting surface

Abstract

The invention essentially relates to the use of a substantially nickel free non-stainless low alloy steel, for manufacturing at least the surface of an item intended to be put into contact with titanium or a titanium alloy, as well as to a method for manufacturing at least the surface of such an article. The invention notably relates the use of this alloy for manufacturing at least the contact surface of a mold for hot forming titanium-based alloys or titanium alloy in the solid-state, or for manufacturing at least the contact surface of tools for densifying and forming bulk titanium alloys or titanium or titanium alloy powders. Items intended to be put in contact with titanium or a titanium alloy may be produced with the invention.

1 - 21 . (canceled)  
     
     
         22 . A method for manufacturing at least the surface of an item to be put into contact with titanium or a titanium alloy for solid-state forming of said titanium or titanium alloy, wherein said method comprises the manufacturing of said surface with a substantially nickel-free non-stainless low alloy steel comprising less than 10% by weight of alloy elements.  
     
     
         23 . A Method for manufacturing at least the surface of an item to be put into contact with titanium or a titanium alloy for solid-state forming of said titanium or titanium alloy, wherein said method comprises the manufacturing of said surface with a substantially nickel-free non-stainless low alloy steel comprising less than 10% by weight of alloy elements, said steel comprising in weight percent: 
 nickel: less than or equal to 2.5%,    chromium: between 0.5 and 4%,    carbon: less than or equal to 1,    balance: iron, as well as unavoidable impurities.    
     
     
         24 . The method of  claim 23 , wherein the steel comprises: 
 nickel: less than or equal to 0.5%    chromium: between 0.8% and 2%,    carbon: less than or equal to 0.4%,    balance: iron, as well as unavoidable impurities.    
     
     
         25 . The method of  claim 23 , wherein the steel further comprises from 0.1 to 4% by weight of molybdenum.  
     
     
         26 . The method of  claim 23 , wherein the steel further comprises from 0.15 to 1% by weight of molybdenum.  
     
     
         27 . The method of  claim 23 , wherein the steel further comprises from 0.05 to 4% by weight of vanadium.  
     
     
         28 . The method of  claim 23 , wherein the steel further comprises from 0.05 to 2% by weight of vanadium.  
     
     
         29 . The method of  claim 23 , wherein the steel further comprises from 0.1 to 1% by weight of vanadium.  
     
     
         30 . The method of  claim 23 , wherein the steel is 18CD4 grade steel.  
     
     
         31 . The method of  claim 23 , wherein the steel is 15CDV6 grade steel.  
     
     
         32 . The method of  claim 23 , comprising the manufacturing with said steel of at least the contact surface of a mold for hot forming of titanium or titanium alloy in the solid state.  
     
     
         33 . The method of  claim 23 , comprising the manufacturing with said steel of tools for densifying or forming titanium or titanium alloy powders.  
     
     
         34 . The method of  claim 23 , comprising the manufacturing with said steel of tools for solid-state forming of bulk titanium or bulk titanium alloy.  
     
     
         35 . The method of  claim 23 , wherein hot casting of said titanium or titanium alloy is performed at a temperature equal to 500° C. and less than 1,000° C.  
     
     
         36 . The method of  claim 23 , comprising molding with said steel of parts in TA6V grade titanium.  
     
     
         37 . The method of  claim 23 , wherein pump impellers in titanium-based alloy are manufactured by tools having at least their contact surface made with said low alloy steel produced by turning or milling.  
     
     
         38 . The method of  claim 23 , wherein annealing of the steel is performed in order to improve the dimensional reproducibility.  
     
     
         39 . An item comprising a contact surface to be put into contact with titanium or a titanium alloy for solid-state forming of said titanium or titanium alloy, wherein at least said surface in contact with the item is produced with a substantially nickel-free non-stainless low alloy steel comprising less than 10% by weight of alloy elements.  
     
     
         40 . The item of  claim 39 , wherein said said steel comprises in weight percent: 
 nickel: less than or equal to 2.5%,    chromium: between 0.5 and 4%,    carbon: less than or equal to 1,    balance: iron, as well as unavoidable impurities.    
     
     
         41 . A tool for densifying and/or forming titanium or titanium alloy powder, wherein at least the surface of the tool to be put into contact with the titanium or titanium alloy in the solid-state, is produced in non-stainless low alloy steel, comprising less than 10% by weight of alloy elements.  
     
     
         42 . The tool of  claim 41 , wherein said steel comprises in weight percent: 
 nickel: less than or equal to 2.5%,    chromium: between 0.5 and 4%,    carbon: less than or equal to 1,    balance: iron, as well as unavoidable impurities.    
     
     
         43 . The tool of  claim 41 , wherein the steel further comprises from 0.1 to 4% by weight of molybdenum.  
     
     
         44 . The tool of  claim 41 , wherein the steel further comprises from 0.05 to 4% by weight of vanadium.  
     
     
         45 . The tool of  claim 41 , wherein the steel is 18CD4 grade steel.  
     
     
         46 . The tool of  claim 41 , wherein the steel is 15CDV6 grade steel.  
     
     
         47 . The tool of  claim 41 , wherein said titanium or titanium alloy is TA6V grade titanium.  
     
     
         48 . A tool for forming bulk titanium or bulk titanium alloy, wherein at least the surface of the tool to be put into contact with titanium or titanium alloy in the solid-state, is produced in non-stainless low alloy steel, comprising less than 10% by weight of alloy elements.  
     
     
         49 . The tool of  claim 48 , wherein said steel comprises in weight percent: 
 nickel: less than or equal to 2.5%,    chromium: between 0.5 and 4%,    carbon: less than or equal to 1,    balance: iron, as well as unavoidable impurities.    
     
     
         50 . The tool of  claim 49 , wherein the steel further comprises from 0.1 to 4% by weight of molybdenum.  
     
     
         51 . The tool of  claim 50 , wherein the steel further comprises from 0.05 to 4% by weight of vanadium.  
     
     
         52 . The tool of  claim 48 , wherein the steel is 18CD4 grade steel.  
     
     
         53 . The tool of  claim 48 , wherein the steel is 15CDV6 grade steel.  
     
     
         54 . The tool of  claim 48 , wherein said titanium or titanium alloy is TA6V grade titanium.  
     
     
         55 . A mold for hot forming of titanium or a titanium alloy in the solid state, wherein at least the surface of the mold intended to be put into contact with the titanium or the titanium alloy in the solid-state is produced in non-stainless low alloy steel, comprising less than 10% by weight of alloy elements.  
     
     
         56 . The mold of  claim 55 , wherein said steel comprises in weight percent: 
 nickel: less than or equal to 2.5%,    chromium: between 0.5 and 4%,    carbon: less than or equal to 1,    balance: iron, as well as unavoidable impurities.    
     
     
         57 . The mold of  claim 56 , wherein the steel further comprises from 0.1 to 4% by weight of molybdenum.  
     
     
         58 . The mold of  claim 56 , wherein the steel further comprises from 0.05 to 4% by weight of vanadium.  
     
     
         59 . The mold of  claim 55 , wherein the steel is 18CD4 grade steel.  
     
     
         60 . The mold of  claim 55 , wherein the steel is 15CDV6 grade steel.  
     
     
         61 . The mold of  claim 55 , wherein said titanium or titanium alloy is TA6V grade titanium.