Title:
MANUFACTURING METHOD FOR SMALL DIAMETER THIN-WALLED PIPE
Document Type and Number:
WIPO Patent Application WO/2011/093055
Kind Code:
A1
Abstract:
Provided is a manufacturing method for a seamless steel pipe in which a small diameter thin-walled pipe is drawn by means of a tapered die (1), which is used as a processing die and is provided with an approaching part (1a) that has a tapered shape, and a bearing part (1b) that delimits the outer diameter in the drawing process, and a plug (2), which is inserted into the inner surface of a pipe (3) that is being drawn while the diameter of the pipe is being reduced by the tapered die (1). As a result of using the tapered die (1) wherein the approaching part (1a) forms an angle (α) of 15 - 20°, it is possible to reduce the striations on the inner surface of the pipe which occur during a hot pipe-manufacturing process without increasing the thickness of the base pipe, and thereby obtain a small diameter thin-walled pipe with a high quality inner surface. In the disclosed manufacturing method for a small diameter thin-walled pipe, it is preferable for the plug (2) to be a semi-floating plug provided with a finishing part (2b), which regulates the finished inner diameter of the pipe and a tapered part (2a), which is contiguous with the finishing part.
Inventors:
HANADA TAKUYA (JP)
OKUI TATSUYA (JP)
OKUI TATSUYA (JP)
Application Number:
PCT/JP2011/000371
Publication Date:
August 04, 2011
Filing Date:
January 25, 2011
Export Citation:
Assignee:
SUMITOMO METAL IND (JP)
HANADA TAKUYA (JP)
OKUI TATSUYA (JP)
HANADA TAKUYA (JP)
OKUI TATSUYA (JP)
International Classes:
B21C3/02; B21C3/16
Foreign References:
| JP2006272396A | 2006-10-12 |
Attorney, Agent or Firm:
MORI, Michio et al. (JP)
Woods Michio (JP)
Woods Michio (JP)
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Claims:
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