Title:
PROCESS FOR PRODUCING SEAMLESS PIPE
Document Type and Number:
WIPO Patent Application WO/2007/110930
Kind Code:
A1
Abstract:
A process for producing a seamless pipe characterized by including a continuous casting step in which a round billet is cast in which the whole region in a central part having a diameter of at least 60 mm in the cross section is constituted of an isometric crystal structure and which has a carbon content of 0.1 mass% or lower and a diameter in terms of cross-section diameter beyond 300 mm. In the process for seamless-pipe production, the round billet produced in the continuous casting step may be pierced/rolled with a piercer under conditions in which the ratio of the billet rotation speed to the billet outer-diameter draft is a value in a range suitable for the ratio of the gorge part diameter to the inlet diameter in the tilting rolls, thereby giving a seamless pipe reduced in defects in the inner surface. As a piercing plug may be used a plug of a suitable shape which is approximately cylindrical and has a spherical rolling part at the plug tip. Thus, Mannesmann fracture and circumferential-direction shear strain are significantly inhibited and no billet nipping failure occurs at all. This process for seamless-pipe production enables a seamless pipe having even higher inner-surface quality to be produced with exceedingly high productivity.
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Inventors:
YAMANAKA, Akihiro (5-33, Kitahama 4-chome, Chuo-ku, Osaka-sh, Osaka 41, 5410041, JP)
山中 章裕 (〒41 大阪府大阪市中央区北浜四丁目５番３３号 住友金属工業株式会社内 Osaka, 5410041, JP)
ADACHI, Manabu (1850 Minato, Wakayama-sh, Wakayama 55, 6408555, JP)
足立 学 (〒55 和歌山県和歌山市湊１８５０番地 株式会社住金鋼鉄和歌山内 Wakayama, 6408555, JP)
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四丁目５番３３号 住友金属工業株式会社内 Osaka, 5410041, JP)
山中 章裕 (〒41 大阪府大阪市中央区北浜四丁目５番３３号 住友金属工業株式会社内 Osaka, 5410041, JP)
ADACHI, Manabu (1850 Minato, Wakayama-sh, Wakayama 55, 6408555, JP)
足立 学 (〒55 和歌山県和歌山市湊１８５０番地 株式会社住金鋼鉄和歌山内 Wakayama, 6408555, JP)
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四丁目５番３３号 住友金属工業株式会社内 Osaka, 5410041, JP)
Application Number:
JP2006/306275
Publication Date:
October 04, 2007
Filing Date:
March 28, 2006
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四丁目５番３３号 Osaka, 5410041, JP)
YAMANAKA, Akihiro (5-33, Kitahama 4-chome, Chuo-ku, Osaka-sh, Osaka 41, 5410041, JP)
山中 章裕 (〒41 大阪府大阪市中央区北浜四丁目５番３３号 住友金属工業株式会社内 Osaka, 5410041, JP)
ADACHI, Manabu (1850 Minato, Wakayama-sh, Wakayama 55, 6408555, JP)
足立 学 (〒55 和歌山県和歌山市湊１８５０番地 株式会社住金鋼鉄和歌山内 Wakayama, 6408555, 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四丁目５番３３号 Osaka, 5410041, JP)
YAMANAKA, Akihiro (5-33, Kitahama 4-chome, Chuo-ku, Osaka-sh, Osaka 41, 5410041, JP)
山中 章裕 (〒41 大阪府大阪市中央区北浜四丁目５番３３号 住友金属工業株式会社内 Osaka, 5410041, JP)
ADACHI, Manabu (1850 Minato, Wakayama-sh, Wakayama 55, 6408555, JP)
足立 学 (〒55 和歌山県和歌山市湊１８５０番地 株式会社住金鋼鉄和歌山内 Wakayama, 6408555, JP)
YAMAKAWA, Tomio (5-33, Kitahama 4-chome, Chuo-ku, Osaka-sh, Osaka 41, 5410041, JP)
International Classes:
B21B19/04; B22D11/00; B22D11/124; B22D27/04
Attorney, Agent or Firm:
MORI, Michio (M. MORI PATENT OFFICE, Amagasaki Building 17-23,Higashinaniwa-cho 5-chome, Amagasaki-sh, Hyogo 92, 6600892, JP)
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