Cu-Mg-P BASED COPPER ALLOY SHEET HAVING EXCELLENT SPRING CRITICAL VALUE CHARACTERISTIC AND FATIGUE RESISTANCE AFTER BENDING, AND METHOD FOR PRODUCING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a Cu-Mg-P based alloy sheet having excellent spring critical value properties and fatigue properties after bending, and a method for producing the same.;SOLUTION: The copper alloy sheet has a composition comprising, by mass, 0.2 to 1.2% Mg and 0.001 to 0.2% P, and the balance Cu with inevitable impurities. In crystal orientation analysis by an EBSD measurement method according to the observation in SEM of the surface parallel to a rolling face, in the case the orientations of all pixels in a measurement area range are measured at the step size of 1.0 μm, and the boundary in which the orientation difference between the adjacent pixels is 15° or higher is defined as a crystal boundary, Brass orientation density is 4 to 19%, Copper orientation density is 2 to 13%, all crystal grain sizes are 10 μm, and the area ratio of the crystal grains with the crystal grain sizes of 5 μm or lower is 75% or higher.;COPYRIGHT: (C)2014,JPO&INPIT