Copper alloy for seamless pipes

Abstract

A seamless pipe copper alloy includes Zr and at least one of Al, Sn, and Zn, with the balance being Cu and unavoidable impurities, the Al content, the Sn content, the Zn content, and the Zr content of the copper alloy satisfying the expressions 0.05≦A+B+C, 0.01≦D≦0.5, and 0.25≦A+B+C+D≦0.8 (wherein A represents the Al content (mass %), B represents the Sn content (mass %), C represents the Zn content (mass %), and D represents the Zr content (mass %)). The seamless pipe copper alloy exhibits excellent workability, high strength, and high thermal conductivity. The seamless pipe copper alloy also shows only a small decrease in strength due to brazing.

1 . A seamless pipe copper alloy comprising Zr and at least one of Al, Sn, and Zn, with the balance being Cu and unavoidable impurities, the Al content, the Sn content, the Zn content, and the Zr content of the seamless pipe copper alloy satisfying the following expressions (1), (2), and (3),
   0.05 ≦A+B+C   (1)     0.01≦D≦0.5  (2)     0.25 ≦A+B+C+D≦ 0.8  (3)   
     wherein A represents the Al content (mass %), B represents the Sn content (mass %), C represents the Zn content (mass %), and D represents the Zr content (mass %). 
   
   
       2 . The seamless pipe copper alloy according to  claim 1 , the seamless pipe copper alloy further comprising at least one of Fe, Ni, Cr, and Co and having a total content of Fe, Ni, Cr, and Co of 0.1 mass % or less. 
   
   
       3 . The seamless pipe copper alloy according to  claim 1 , the seamless pipe copper alloy having a P content of 0.004 to 0.04 mass %. 
   
   
       4 . The seamless pipe copper alloy according to  claim 2 , the seamless pipe copper alloy having a P content of to 0.04 mass %.