Title:
PRODUCTION OF CHILLED WATER TYPE PITTING CORROSION RESISTANT COPPER TUBE
Document Type and Number:
Japanese Patent JP3907074
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide a method for producing a copper tube for piping by which the content of residual carbon in a copper tube for piping car remarkably be reduced, the generation of pitting corrosion in the copper tube can remarkably be reduced, the excellent adhesion for coating the inside of tube is obtained, and the occurrence of troubles in the piping system is eliminated as well.
SOLUTION: In the production of a soft or semihard copper tube for piping in which annealing for refining is executed after reduction working, at the time of annealing, an oxidizing gas is fed to the inside of the copper tube, its temp. is raised, thereafter, the feed of the oxidizing gas is stopped, its temp. is raised, lubricating oil remaining in the tube is decomposed by combustion, next, a nonoxidizing gas is fed thereto, and, while the formation of copper oxide is prevented, its temp. is raised to an annealing one. After annealing, it is preferable that the feed of the nonoxidizing gas is continued till it is cooled to a temp. region lower than the forming temp. of copper oxide.
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Inventors:
Atsumi Tetsuro
Kozo Kono
Masaya Imai
Kozo Kono
Masaya Imai
Application Number:
JP8483696A
Publication Date:
April 18, 2007
Filing Date:
March 13, 1996
Export Citation:
Assignee:
Sumitomo Light Metal Industry Co., Ltd.
International Classes:
C21D9/08; E03C1/02; C21D1/74; C22F1/02; C22F1/08; C23G5/00; (IPC1-7): C21D9/08; C21D1/74; C22F1/02; C22F1/08; C23G5/00; E03C1/02
Domestic Patent References:
| JP6330265A | ||||
| JP57007344A | ||||
| JP6228649A |
Attorney, Agent or Firm:
Yasuo Fukuda
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