Title:
HIGH STRENGTH STEEL SHEET HAVING EXCELLENT DEFORMABILITY, HIGH STRENGTH STEEL PIPE AND PRODUCTION METHOD THEREOF
Document Type and Number:
Japanese Patent JP3869747
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide a line pipe having a high deformability of X60 to 100 class in the API standards which also has low temperature toughness and high productivity, and to provide a steel sheet of the stock, and to provide a method of producing them.
SOLUTION: In the high strength steel sheet having excellent deformability, ferrite is finely dispersed in a low temperature transformed structure essentially consisting of bainitic phases in an area ratio of 5 to 40%, and the particle diameters of almost all the ferritic phase are smaller than the means particle diameter of the bainitic phases. Further, in a large-sized steel pipe, the above structure is formed, and YS (yield strength)/TS (tensile strength) is ≤0.95, and YS×uEl (uniform elongation) is ≥5,000.
Inventors:
Asahi Hitoshi
Takuya Hara
Yasuhiro Shinohara
Takuya Hara
Yasuhiro Shinohara
Application Number:
JP2002106536A
Publication Date:
January 17, 2007
Filing Date:
April 09, 2002
Export Citation:
Assignee:
Nippon Steel Corporation
International Classes:
B23K9/23; C22C38/00; B21C37/08; B23K13/00; C21D8/02; C21D8/10; C21D9/46; C22C38/02; C22C38/04; C22C38/12; C22C38/14; C22C38/58; B23K101/06; B23K103/04; (IPC1-7): C22C38/00; B21C37/08; B23K9/23; B23K13/00; C21D8/02; C21D8/10; C21D9/46; C22C38/58; //B23K101:06; B23K103:04
Domestic Patent References:
| JP8199291A | ||||
| JP7126797A | ||||
| JP10158778A | ||||
| JP2001288512A | ||||
| JP6136482A | ||||
| JP5255744A |
Attorney, Agent or Firm:
Takashi Ishida
Jun Tsuruta
Hiroshi Kamematsu
Masaya Nishiyama
Jun Tsuruta
Hiroshi Kamematsu
Masaya Nishiyama
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