Beta type titanium alloy and manufacturing method thereof

Abstract

The present invention provides a β type titanium alloy characterized by consisting of, by mass %, V: 15 to 25%, Al: 2.5 to 5%, Sn: 0.5 to 4%, O (Oxygen): not more than 0.20%, H: not more than 0.03%, Fe: not more than 0.40%, C: not more than 0.05% and N: not more than 0.02%, and the balance Ti and impurities. The present invention also provides a method of manufacturing a β type titanium alloy characterized by comprising the following steps (a) to (c): (a) Preparing a β type titanium alloy consisting of, by mass %, V: 15 to 25%, Al: 2.5 to 5%, Sn: 0.5 to 4%, O (Oxygen): not more than 0.20%, H: not more than 0.03%, Fe: not more than 0.40%, C: not more than 0.05% and N: not more than 0.02%, and the balance Ti and impurities. (b) Pickling the B type titanium alloy in an aqueous solution including 3 to 40 mass % of HF, and (c) Further pickling the B type titanium alloy in an aqueous solution including 3 to 6 mass % of HF and 5 to 20 mass % of HNO 3 .

1 . A β type titanium alloy characterized by consisting of, by mass %, V: 15 to 25%, Al: 2.5 to 5%, Sn: 0.5 to 4%, O (Oxygen): not more than 0.20%, H: not more than 0.03%, Fe: not more than 0.40%, C: not more than 0.05% and N: not more than 0.02%, and the balance Ti and impurities.  
   
   
       2 . A β type titanium alloy characterized by consisting of, by mass %, V: 15 to 25%, Al: 2.5 to 5%, Sn: 0.5 to 4%, O (Oxygen): not more than 0.12%, H: not more than 0.03%, Fe: not more than 0.15%, C: not more than 0.05% and N: not more than 0.02%, and the balance Ti and impurities.  
   
   
       3 . A β type titanium alloy characterized by consisting of, by mass %, V: 15 to 25%, Al: 2.5 to 5%, Sn: 0.5 to 4%, O (Oxygen): not more than 0.20%, H: not more than 0.03%, Fe: not more than 0.40%, C: not more than 0.05% and N: not more than 0.02%, and less than 3% of at least one element selected from Zr, Mo, Nb, Ta, Cr, Mn, Ni, Pd and Si, and the balance Ti and impurities.  
   
   
       4 . A method of manufacturing a β type titanium alloy characterized by comprising the following steps (a) to (c): 
 (a) Preparing a β type titanium alloy consisting of, by mass %, V: 15 to 25%, Al: 2.5 to 5%, Sn: 0.5 to 4%, O (Oxygen): not more than 0.20%, H: not more than 0.03%, Fe: not more than 0.40%, C: not more than 0.05% and N: not more than 0.02%, and the balance Ti and impurities.    (b) Pickling the β type titanium alloy in an aqueous solution including 3 to 40 mass % of HF, and    (c) Further pickling the β type titanium alloy in an aqueous solution including 3 to 6 mass % of HF and 5 to 20 mass % of HNO 3 .    
   
   
       5 . A method of manufacturing a β type titanium alloy characterized by comprising the following steps (a) to (c): 
 (a) Preparing a β type titanium alloy consisting of, by mass %, V: 15 to 25%, Al: 2.5 to 5%, Sn: 0.5 to 4%, O (Oxygen): not more than 0.20%, H: not more than 0.03%, Fe: not more than 0.40%, C: not more than 0.05% and N: not more than 0.02%, and less than 3% of at least one element selected from Zr, Mo, Nb, Ta, Cr, Mn, Ni, Pd and Si, and the balance Ti and impurities.    (b) Pickling the β type titanium alloy in an aqueous solution including 3 to 40 mass % of HF, and    (c) Further pickling the β type titanium alloy in an aqueous solution including 3 to 6 mass % of HF and 5 to 20 mass % of HNO 3 .