| 摘要 |
PURPOSE:To easily obtain an automotive heat-exchanger fin material free from defects, by coating the surface of a copper-alloy bar with a metal electrochemically based that Cu or alloys thereof and then carrying out cold working at the prescribed draft by a single stage. CONSTITUTION:A copper-alloy bar is coated with a metal electrochemically baser than Cu or alloys thereof consisting of one element among Zn, Al, Ni, Sn, Pb, Fe, Bi, Cd, and Co or alloys thereof by means of electroplating, etc. Subsequently, the coated copper-alloy bar is subjected to cold working at 40-80% draft by a single stage. By this method, automotive heat-exchanger fin material improved in corrosion resistance can be obtained. Moreover, as the copper-alloy bar, an alloy prepared by adding small amounts of Sn, Ag, Cd, P, etc., to Cu in the ranges causing no deterioration in heat transferability in order to improve strength and corrosion resistance is used as usual. |
