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Title:
継目無管の製造方法
Document Type and Number:
Japanese Patent JP4315155
Kind Code:
B2
Abstract:
A method of manufacturing a seamless tube by the invention can duly control the rotary forging effect without miss-rolling such as defective onset engagement with rolls by satisfying either of (1) - (3) formulas below, dependent on a given range of roll diameter ratio Dg / D1, prevent the occurrence of internal surface flaws at the top of the work material attributable to deteriorated hot workability, and further prevent the occurrence of said flaws over the remaining length without altering parameters for piercing-rolling process. Thus, the invention can be widely utilized as an excellent manufacturing method for said tube: in €‰€ƒcase €‰€ƒof €‰ €ƒD g / D 1 < 1.1 , 23 ‰¦ N / ( D f / 100 ) ‰¦ 40 , in €‰€ƒcase €‰€ƒof €‰€ƒ 1.1 ‰¦ D g / D 1 < 1.5 , 20 ‰¦ N / ( D f / 100 ) ‰¦ 44 , in €‰€ƒcase €‰€ƒof €‰€ƒ 1.5 ‰¦ D g / D 1 ‰¦ 1.8 , 20 ‰¦ N / ( D f / 100 ) ‰¦ 48.

Inventors:
Tomio Yamakawa
Kazumune Shimoda
Application Number:
JP2005506398A
Publication Date:
August 19, 2009
Filing Date:
May 20, 2004
Export Citation:
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Assignee:
SUMITOMO METAL INDUSTRIES,LTD.
International Classes:
B21B19/04; B21B27/02
Domestic Patent References:
JP61003605A
JP6218406A
JP2000140911A
JP3013222A
JP62282713A
Foreign References:
WO1996021526A1
Attorney, Agent or Firm:
Michio Mori