Title:
HIGH STRENGTH STEEL SHEET AND METHOD FOR MANUFACTURING THE SAME
Document Type and Number:
Japanese Patent JP2021172838
Kind Code:
A
Abstract:
To provide a high strength steel sheet and a method for manufacturing the same.SOLUTION: A high strength steel sheet consists of a specific component composition. In a steel structure, the total area rate of martensite and lower bainite is 40-100%; the total area rate of fresh martensite and retained austenite is 0-20%; the area ratio of perlite is 3% or less; the average aspect ratio of old austenite grains is 5.0 or less; the amount of B deposited as BN is 0.0005-0.010%, by mass%; and a relationship between the total area rate (%) of structures except the martensite, the lower bainite, the fresh martensite and the retained austenite and a tensile strength (MPa) satisfies the formula (1), V(S)≤0.0001×TS2-0.4×TS+400....(1).SELECTED DRAWING: None
Inventors:
KIMURA HIDEYUKI
HASEGAWA HIROSHI
NAKAGAITO TATSUYA
HASEGAWA HIROSHI
NAKAGAITO TATSUYA
Application Number:
JP2020075833A
Publication Date:
November 01, 2021
Filing Date:
April 22, 2020
Export Citation:
Assignee:
JFE STEEL CORP
International Classes:
C22C38/00; C21D9/46; C22C38/06; C22C38/60
Domestic Patent References:
| JP2018193614A | 2018-12-06 | |||
| JP2019044217A | 2019-03-22 | |||
| JP2002309344A | 2002-10-23 | |||
| JP2016216808A | 2016-12-22 | |||
| JP2004068050A | 2004-03-04 | |||
| JPH10168521A | 1998-06-23 |
Foreign References:
| WO2010032428A1 | 2010-03-25 | |||
| WO2016157896A1 | 2016-10-06 | |||
| WO2020002285A1 | 2020-01-02 |
Attorney, Agent or Firm:
Isomura Tetsuro
Akira Kumasaka
Tetsuya Sakai
Kazuhiro Mori
Akira Kumasaka
Tetsuya Sakai
Kazuhiro Mori
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