Title:
SOUR RESISTANT STEEL SHEET
Document Type and Number:
Japanese Patent JP2017155290
Kind Code:
A
Abstract:
PROBLEM TO BE SOLVED: To provide an API 5L X65 class sour resistant steel sheet having sheet thickness of 36.0 mm or more and securing HIC resistance and DWTT properties of a steel sheet at a low temperature of -30°C or less.SOLUTION: There is provided a sour resistant steel sheet containing, by mass%, Ca:0.0005 to 0.0030%, Zr:0.0005% to 0.03%, S:0.0001% to 0.0010%, O:0.0010% to 0.0030% with limitation of Nb:0.004% or less, satisfying the following formula (1) and having average of effective crystal grain diameter at a position of 1/2 of sheet thickness from a surface in a sheet thickness direction of 25 μm. 1.0≤(Ca-0.83×O)/(1.25×S)+(Zr-1.90×O)/(2.85×S)≤10.0 (1), where each mathematics is calculated as zero when (Ca-0.83×O) and (Zr-1.90×O) are negative value.SELECTED DRAWING: None
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Inventors:
KOJIMA AKIHIKO
ISHIKAWA KYOHEI
SHINOHARA YASUHIRO
ISHIKAWA KYOHEI
SHINOHARA YASUHIRO
Application Number:
JP2016039877A
Publication Date:
September 07, 2017
Filing Date:
March 02, 2016
Export Citation:
Assignee:
NIPPON STEEL & SUMITOMO METAL CORP
International Classes:
C22C38/00; C22C38/14; C22C38/58
Domestic Patent References:
| JP2010209460A | 2010-09-24 | |||
| JP2017110249A | 2017-06-22 |
Foreign References:
| WO2010052927A1 | 2010-05-14 | |||
| WO2010052928A1 | 2010-05-14 | |||
| WO2010052926A1 | 2010-05-14 |
Attorney, Agent or Firm:
Atsushi Aoki
Takashi Ishida
Tetsuji Koga
Hiroshi Kamematsu
Fukuchi Ritsuo
Hideo Tokunaga
Nakamura Asayuki
Takashi Ishida
Tetsuji Koga
Hiroshi Kamematsu
Fukuchi Ritsuo
Hideo Tokunaga
Nakamura Asayuki