Title:
HIGH-STRENGTH STEEL PIPE, STEEL PLATE FOR HIGH-STRENGTH STEEL PIPE, AND PROCESSES FOR PRODUCING THESE
Document Type and Number:
WIPO Patent Application WO/2011/042936
Kind Code:
A1
Abstract:
A steel pipe produced by cold-forming a steel plate and then subjecting the formed plate to seam-welding, wherein (i) the steel plate contains carbon, manganese, niobium, and titanium, has a weld crack susceptibility composition (Pcm) of 0.23 or less, and has a metallographic structure including bainite and ferrite and (ii) the ratio of the thickness of the steel plate (t) to the outer diameter (D) of the steel pipe, t/D, is 0.030 or lower and the steel pipe has a circumferential yield ratio, measured using a round-bar test piece, of 0.90 or lower.
Inventors:
ASAHI, Hitoshi (6-1 Marunouchi 2-chome, Chiyoda-k, Tokyo 71, 〒1008071, JP)
朝日均 (〒71 東京都千代田区丸の内二丁目６番１号 新日本製鐵株式会社内 Tokyo, 〒1008071, JP)
HARA, Takuya (6-1 Marunouchi 2-chome, Chiyoda-k, Tokyo 71, 〒1008071, JP)
朝日均 (〒71 東京都千代田区丸の内二丁目６番１号 新日本製鐵株式会社内 Tokyo, 〒1008071, JP)
HARA, Takuya (6-1 Marunouchi 2-chome, Chiyoda-k, Tokyo 71, 〒1008071, JP)
Application Number:
JP2009/005263
Publication Date:
April 14, 2011
Filing Date:
October 08, 2009
Export Citation:
Assignee:
NIPPON STEEL CORPORATION (6-1 Marunouchi 2-chome, Chiyoda-ku Tokyo, 71, 〒1008071, JP)
新日本製鐵株式会社 (〒71 東京都千代田区丸の内二丁目６番１号 Tokyo, 〒1008071, JP)
ASAHI, Hitoshi (6-1 Marunouchi 2-chome, Chiyoda-k, Tokyo 71, 〒1008071, JP)
朝日均 (〒71 東京都千代田区丸の内二丁目６番１号 新日本製鐵株式会社内 Tokyo, 〒1008071, JP)
新日本製鐵株式会社 (〒71 東京都千代田区丸の内二丁目６番１号 Tokyo, 〒1008071, JP)
ASAHI, Hitoshi (6-1 Marunouchi 2-chome, Chiyoda-k, Tokyo 71, 〒1008071, JP)
朝日均 (〒71 東京都千代田区丸の内二丁目６番１号 新日本製鐵株式会社内 Tokyo, 〒1008071, JP)
International Classes:
C22C38/00; B21C37/08; C21D8/02; C22C38/14; C22C38/58
Attorney, Agent or Firm:
SHIGA, Masatake et al. (1-9-2, Marunouchi Chiyoda-k, Tokyo 20, 〒1006620, JP)
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