Title:
METHOD FOR PRODUCING SEAMLESS PIPE
Document Type and Number:
WIPO Patent Application WO/2008/020510
Kind Code:
A1
Abstract:
A high quality hollow material pipe is produced surely by controlling the number
of times of rotary forging and shear deformation in an unsteady region during
biting, preventing occurrence of flaw on the inner surface resulting from rotary
forging effect and/or shear deformation at the top of the hollow material pipe,
preventing uneven thickness from worsening at the top of the hollow material
pipe, preventing mis-roll such as poor biting or releasing, and preventing the
outside diameter at the bottom of the hollow material pipe from increasing. Using
a pair of inclination rolls, a pair of disc rolls and a plug, the ratio (Dg/d) between
thediameter (Dg) at the gorge portion of the inclination roll and the outside
diameter (d) of a billet, the ratio (Dd/d) between the diameter (Dd) at the bottom
of groove of the disc roll and (d), the ratio (Dd/Dg) between (Dg) and (Dd), the
entrance face angle (θ1) of the inclination roll, and the square root of
product (Ns×Df)0.5 of the number of revolutions (Ns) of the billet
in the biting unsteady region and the outside diameter reduction in thickness
(Df) of that billet are made to satisfy a predetermined relational expression,
and punching rolling is performed while the billet is rotary-moved to obtain
a hollow material pipe and produce a seamless pipe finally.
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Inventors:
YAMAKAWA, Tomio (5-33, Kitahama 4-chome, Chuo-ku, Osaka-sh, Osaka 41, 5410041, JP)
山川 富夫 (〒41 大阪府大阪市中央区北浜４丁目５番３３号 住友金属工業株式会社内 Osaka, 5410041, JP)
山川 富夫 (〒41 大阪府大阪市中央区北浜４丁目５番３３号 住友金属工業株式会社内 Osaka, 5410041, JP)
Application Number:
JP2007/063227
Publication Date:
February 21, 2008
Filing Date:
July 02, 2007
Export Citation:
Assignee:
SUMITOMO METAL INDUSTRIES, LTD. (5-33, Kitahama 4-chome Chuo-ku, Osaka-sh, Osaka 41, 5410041, JP)
住友金属工業株式会社 (〒41 大阪府大阪市中央区北浜４丁目５番３３号 Osaka, 5410041, JP)
YAMAKAWA, Tomio (5-33, Kitahama 4-chome, Chuo-ku, Osaka-sh, Osaka 41, 5410041, JP)
住友金属工業株式会社 (〒41 大阪府大阪市中央区北浜４丁目５番３３号 Osaka, 5410041, JP)
YAMAKAWA, Tomio (5-33, Kitahama 4-chome, Chuo-ku, Osaka-sh, Osaka 41, 5410041, JP)
International Classes:
B21B19/04; B21B23/00; B21B27/02; B21B19/00; B21B23/00; B21B27/02
Attorney, Agent or Firm:
HIROSE, Shoichi (Tozan Building, 4-2 Nihonbashi Honcho 4-chom, Chuo-ku Tokyo 23, 1030023, JP)
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