Patent ID: 9121086
Filing Date: 2015-09-01
Classification: B21B,C22C,C22F,H01B

Abstract:
1. A method for manufacturing a copper alloy sheet, sequentially comprising: subjecting an ingot to a hot rolling process to obtain a copper alloy material; subjecting the copper alloy material to a cold rolling process; subjecting the copper alloy material to a recrystallization thermal treatment process; and subjecting the copper alloy material to a cold finishing rolling process, wherein a hot rolling initial temperature of the hot rolling process is 800° C. to 920° C., a cooling rate of the copper alloy material in a temperature range from a temperature after final rolling to 350° C. or 650° C. to 350° C. is 1° C./second or more, wherein a cold working rate in the cold rolling process is 55% or more, wherein the recrystallization thermal treatment process includes a heating step of heating the copper alloy material to a predetermined temperature, a holding step of holding the copper alloy material at a predetermined temperature for a predetermined time after the heating step and a cooling step of cooling the copper alloy material to a predetermined temperature after the holding step, wherein in the recrystallization thermal treatment process, when a peak temperature of the copper alloy material is denoted by Tmax (° C.), a holding time in a temperature range of a temperature 50° C. lower than the peak temperature of the copper alloy material to the peak temperature is denoted by tm (min), and the cold working rate in the cold rolling step is denoted by RE (%), 540≦Tmax≦780, 0.04≦tm≦2, and 450≦{Tmax−40×tm wherein an average crystal grain diameter of the copper alloy material before the cold finishing rolling process is 1.2 μm to 5.0 μm, round or oval precipitates are present in the copper alloy material before the cold finishing rolling process, an average grain diameter of the precipitates is 4.0 nm to 25.0 nm or a proportion of precipitates having a grain diameter of 4.0 nm to 25.0 nm in the precipitates is 70% or more, wherein the copper alloy sheet contains 5.0 mass % to 12.0 mass % of Zn, 1.1 mass % to 2.5 mass % of Sn, 0.01 mass % to 0.09 mass % of P and 0.6 mass % to 1.5 mass % of Ni with a remainder of Cu and inevitable impurities, and wherein a content of Zn [Zn] mass %, a content of Sn [Sn] mass %, a content of P [P] mass % and a content of Ni [Ni] mass % have a relationship of 20≦[Zn]+7×[Sn]+15×[P]+4.5×[Ni]≦32.