| 摘要 |
PROBLEM TO BE SOLVED: To provide a method, in which increasing of production cost is not incurred, a problem in environment does not exist, carbonaceous film generated in a pipe can be effectively removed, a novel temper-annealing treatment that can be profitably applied to a treatment of a copper pipe of a coil shape form is performed, and a copper pipe resistant against cold water pitting corrosion can be profitably obtained, in production of a level wound coil composed of a phosphorous-deoxidized copper pipe for pipe arrangement or the like.SOLUTION: In a level wound coil that is obtained by that a copper pipe composed of a phosphorous-deoxidized copper subjected to a prescribed drawing work is wound in a coil form, hydrogen gas having at least 90% of purity is encapsulated in the copper pipe, then annealing treatment is performed by being heated at a temperature of 350-500°C in a reduction atmosphere or inert atmosphere. |
