Title:
METHOD FOR FORMING CORROSION-RESISTANT COATING IN PROCESS FOR PRODUCING STEEL PIPE
Document Type and Number:
WIPO Patent Application WO/2006/064803
Kind Code:
A1
Abstract:
[PROBLEMS] To improve the corrosion resistance by converting a pipe making step and a coating forming step to a continuous step and forming a corrosion-resistant coating having no pin-holes. [MEANS FOR SOLVING PROBLEMS] On the way of the cooling after the heating of a steel tube having been produced with a pipe making machine (2), a corrosion-resistant coating is formed on the surface of the perimeter of the steel tube in an atmosphere of a reducing gas or an inert gas, and then when the temperature of the corrosion-resistant coating is lowered to 75 to 95 % of the melting point of the corrosion-resistant coating, the corrosion-resistant coating is pressed so as to have a reduced thickness by the use of a pressing roll, to thereby press pin-holes in the corrosion-resistant coating and closely attach them to the surface and simultaneously diffuse them at a high temperature.
Inventors:
USUI TAKAAKI (JP)
SUGIYAMA MOTOHARU (JP)
SUGIYAMA MOTOHARU (JP)
Application Number:
PCT/JP2005/022879
Publication Date:
June 22, 2006
Filing Date:
December 13, 2005
Export Citation:
Assignee:
USUI KOKUSAI SANGYO KK (JP)
USUI TAKAAKI (JP)
SUGIYAMA MOTOHARU (JP)
USUI TAKAAKI (JP)
SUGIYAMA MOTOHARU (JP)
International Classes:
C25D5/00; B21C37/06; C25D7/04
Foreign References:
| JP2000005816A | 2000-01-11 | |||
| JPS4842962A | 1973-06-21 | |||
| JPS61124559A | 1986-06-12 | |||
| JPH09174154A | 1997-07-08 | |||
| JPH05104253A | 1993-04-27 |
Attorney, Agent or Firm:
Oshida, Yoshitaka (3-12 Ginza 3-chome, Chuo-k, Tokyo 61, JP)
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