Title:
延性破壊特性に優れた高強度鋼板及び高強度溶接鋼管並びにそれらの製造方法
Document Type and Number:
Japanese Patent JP5068645
Kind Code:
B2
Abstract:
The present invention provides high strength steel plate and high strength welded pipe excellent in ductile fracture characteristic and methods of production of the same, that is, high strength steel plate excellent in ductile fracture characteristic, and high strength welded pipe using that steel plate as a base material, having a tensile strength corresponding to the X100 class of the API standard, containing, by mass%, C:0.01 to 0.5%, Si:0.01 to 3%, Mn:0.1 to 5%, P:0.03% or less, and S:0.03% or less and a balance of Fe and unavoidable impurities, having a microstructure comprised of, by area ratio, 1 to 60% of ferrite and the balance of bainite and martensite, having a maximum value of the {100} accumulation degree of the cross-section rotated 20 to 50° from the plate thickness cross-section about the rolling direction as an axis of 3 or less, and having plate thickness parallel cracks measured by ultrasonic flaw detection of less than 1 mm.
Inventors:
Takuya Hara
Yasuhiro Shinohara
Asahi Hitoshi
Yoshio Terada
Yasuhiro Shinohara
Asahi Hitoshi
Yoshio Terada
Application Number:
JP2007512405A
Publication Date:
November 07, 2012
Filing Date:
April 19, 2005
Export Citation:
Assignee:
Nippon Steel Corporation
International Classes:
C22C38/00; B21B1/26; B21B3/00; B21C37/08; B23K9/025; B23K9/18; B23K9/23; B23K35/30; C21D8/02; C22C38/58; B23K101/06; B23K103/04
Domestic Patent References:
| JP3470632B2 | 2003-11-25 | |||
| JP2002285283A | 2002-10-03 | |||
| JP2003096517A | 2003-04-03 | |||
| JPH10147846A | 1998-06-02 | |||
| JP2005146407A | 2005-06-09 |
Attorney, Agent or Firm:
Atsushi Aoki
Takashi Ishida
Tetsuji Koga
Hiroshi Kamematsu
Nagasaka Tomoyasu
Takashi Ishida
Tetsuji Koga
Hiroshi Kamematsu
Nagasaka Tomoyasu