Bending modified cross-section copper alloy sheet and a method for manufacturing the same anisotropy of processing and excellent low stress relaxation properties

摘要

PROBLEM TO BE SOLVED: To provide a Cu-Cr-Zr based copper alloy sheet with a deformed cross section which has reduced anisotropy of bending, has satisfactory stress relaxation resistance and has excellent dimensional accuracy, and a method for producing the same.;SOLUTION: In the copper alloy sheet with a deformed cross section, a thick part and a thin part are arranged in a width direction. The copper alloy sheet has a composition composed of, by mass, 0.05 to 0.2% Zr and 0.2 to 0.4% Cr, and the balance Cu with inevitable impurities. Regarding its bendability as a ratio between the minimum bend radius R at which cracks are not generated in a 90° W bending test in accordance with JIS H 3110 and the sheet thickness, t (R/t), provided that the bendability in a Bad Way direction (R/t) is defined as R₂ and the bendability in a Good Way direction is defined as R₁, R₂/R₁ is 0.8 to 1.7, and (the GOS1 of the thin part)/(the GOS2 of the thick part) observed by an EBSD method by a scanning electron microscope with a backscattered electron diffraction image system is 0.9 to 1.4.;COPYRIGHT: (C)2013,JPO&INPIT