Title:
HIGH-STRENGTH SEAMLESS STEEL PIPE FOR MECHANICAL STRUCTURE WHICH HAS EXCELLENT TOUGHNESS AND WELDABILITY, AND METHOD FOR MANUFACTURE THEREOF
Document Type and Number:
WIPO Patent Application WO/2007/114413
Kind Code:
A1
Abstract:
Disclosed is a high-strength seamless steel pipe for use in a mechanical structure, which has the following chemical composition (by mass): C: not less than 0.03 and less than 0.1%; Mn: 0.8 to 2.5%; Ti: 0.005 to 0.035%; Nb: 0.003 to 0.04%; B: 0.0003 to 0.003%; Si: not more than 0.5%; Al: not more than 0.05%; P: not more than 0.015%; S: not more than 0.008%; and N: not more than 0.008%; and at least one component selected from the following components: Ni: 0.1 to 1.5%; Cr: 0.1 to 1.5%; Cu: 0.1 to 1.0%; and Mo: 0.05 to 0.5%; with the remainder being Fe and unavoidable impurities. In the steel pipe, the metallographic structure is a single structure comprising self-tempered martensite or a mixed structure comprising self-tempered martensite and lower bainite. The high-strength seamless steel pipe has excellent toughness and weldability.
Inventors:
SHINOHARA, Yasuhiro (20-1 Shintomi, Futtsu-sh, Chiba 11, 2938511, JP)
篠原康浩 (〒11 千葉県富津市新富２０－１新日本製鐵株式会社 技術開発本部内 Chiba, 2938511, JP)
ISHIZUKA, Tetsuo (20-1 Shintomi, Futtsu-sh, Chiba 11, 2938511, JP)
石塚哲夫 (〒11 千葉県富津市新富２０－１新日本製鐵株式会社 技術開発本部内 Chiba, 2938511, JP)
INOUE, Kazuhiro (3-1 Funado 4-chome, Itabashi-k, Tokyo 41, 1740041, JP)
井上和洋 (〒41 東京都板橋区舟渡４丁目３番１号新日本製鐵株式会社 東京製造所内 Tokyo, 1740041, JP)
篠原康浩 (〒11 千葉県富津市新富２０－１新日本製鐵株式会社 技術開発本部内 Chiba, 2938511, JP)
ISHIZUKA, Tetsuo (20-1 Shintomi, Futtsu-sh, Chiba 11, 2938511, JP)
石塚哲夫 (〒11 千葉県富津市新富２０－１新日本製鐵株式会社 技術開発本部内 Chiba, 2938511, JP)
INOUE, Kazuhiro (3-1 Funado 4-chome, Itabashi-k, Tokyo 41, 1740041, JP)
井上和洋 (〒41 東京都板橋区舟渡４丁目３番１号新日本製鐵株式会社 東京製造所内 Tokyo, 1740041, JP)
Application Number:
JP2007/057360
Publication Date:
October 11, 2007
Filing Date:
March 27, 2007
Export Citation:
Assignee:
NIPPON STEEL CORPORATION (6-3 Otemachi 2-chome, Chiyoda-ku Tokyo, 71, 1008071, JP)
新日本製鐵株式会社 (〒71 東京都千代田区大手町二丁目６番３号 Tokyo, 1008071, JP)
SHINOHARA, Yasuhiro (20-1 Shintomi, Futtsu-sh, Chiba 11, 2938511, JP)
篠原康浩 (〒11 千葉県富津市新富２０－１新日本製鐵株式会社 技術開発本部内 Chiba, 2938511, JP)
ISHIZUKA, Tetsuo (20-1 Shintomi, Futtsu-sh, Chiba 11, 2938511, JP)
石塚哲夫 (〒11 千葉県富津市新富２０－１新日本製鐵株式会社 技術開発本部内 Chiba, 2938511, JP)
INOUE, Kazuhiro (3-1 Funado 4-chome, Itabashi-k, Tokyo 41, 1740041, JP)
新日本製鐵株式会社 (〒71 東京都千代田区大手町二丁目６番３号 Tokyo, 1008071, JP)
SHINOHARA, Yasuhiro (20-1 Shintomi, Futtsu-sh, Chiba 11, 2938511, JP)
篠原康浩 (〒11 千葉県富津市新富２０－１新日本製鐵株式会社 技術開発本部内 Chiba, 2938511, JP)
ISHIZUKA, Tetsuo (20-1 Shintomi, Futtsu-sh, Chiba 11, 2938511, JP)
石塚哲夫 (〒11 千葉県富津市新富２０－１新日本製鐵株式会社 技術開発本部内 Chiba, 2938511, JP)
INOUE, Kazuhiro (3-1 Funado 4-chome, Itabashi-k, Tokyo 41, 1740041, JP)
International Classes:
C22C38/00; B21B17/00; B21B45/02; B21C23/08; C21D8/10; C21D9/08; C22C38/58
Attorney, Agent or Firm:
AOKI, Atsushi et al. (SEIWA PATENT & LAW, Toranomon 37 Mori Bldg. 5-1,Toranomon 3-chome, Minato-k, Tokyo 23, 1058423, JP)