| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a copper alloy tube suitable to a heat-pump water heater, wherein the scale is hardly stuck without depending on the flowing-passage shape. <P>SOLUTION: The copper alloy tube wherein calcium carbonate is hardly stuck as the scale, is manufactured as follows. The copper alloy containing 0.24-0.30 mass% Sn, 0.03-0.05 mass% Zn, 0.004-0.015 mass% P and the balance Cu with inevitable impurities, is subjected to hot-extruding, rolling and extension, to form a prescribed shape and size tube, and Sn, Zr, P are condensed on the surface by performing an annealing with the heat-treatment at 600-800°C for 20 min. or more. <P>COPYRIGHT: (C)2010,JPO&INPIT |
