| 摘要 |
PROBLEM TO BE SOLVED: To provide a seamless tube made of a copper alloy having high strengh and capable of conducting hairpin flexure normally.SOLUTION: A level wound coil has a seamless tube which is wound cylindrically and regularly in a multilayer, materials of the seamless tube wound on the level wound coil is a copper alloy containing Sn of 0.58 to 0.72 mass%, Zr of 0.04 to 0.15 mass%, Fe of 0.01 to 0.10 mass% and P of 0.004 to 0.015 mass% and the balance Cu with inevitable impurities, a ratio of inner thickness (mm) to outer thickness (mm) of the seamless tube wound on the level wound coil (t/D) is 0.037 or less, tensile strength of the seamless tube wound on the level wound coil (σ) of 305 MPa or more, 0.2% bearing force (σ) of 190 MPa or less and elongation (δ) of 36% or more. |
