Title:
高強度鋼板およびその製造方法
Document Type and Number:
Japanese Patent JP6875916
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide a high strength steel sheet having high levels of tensile strength (TS), yield ratio (YR), product of (TS) and all elongation (EL) (TS×EL), LDR and hole expandability (λ) and a manufacturing method therefor.SOLUTION: There is provided a high strength steel sheet containing C:0.15 mass% to 0.35 mass%, total of Si and Al:0.5 mass% to 3.0 mass%, Mn:1.0 mass% to 4.0 mass%, P:0.05 mass% or less, S:0.01 mass% or less and the balance Fe with inevitable impurities and having a steel structure with ferrite fraction of 5% or less, total fraction of tempered martensite and tempered bainite of 60% or more and retained austenite amount of 10% or more, average size of MA of 3 μm or less and average size of the retained austenite of 1.0 μm, and the retained austenite with size of 1.5 μm or more being 2% or more of the total retained austenite amount.SELECTED DRAWING: Figure 1
Inventors:
Toshio Murakami
Shigeo Otani
Yuichi Nimura
Kakiuchi Elijah
Murata Tadao
Shigeo Otani
Yuichi Nimura
Kakiuchi Elijah
Murata Tadao
Application Number:
JP2017072133A
Publication Date:
May 26, 2021
Filing Date:
March 31, 2017
Export Citation:
Assignee:
KABUSHIKI KAISHA KOBE SEIKO SHO
International Classes:
C22C38/00; C21D9/46; C22C38/06; C22C38/58
Domestic Patent References:
| JP2014034716A | ||||
| JP2015218365A | ||||
| JP2014508854A | ||||
| JP2015516511A |
Attorney, Agent or Firm:
Takuji Yamada
Norihito Yamao
Noriko Cauldron
Norihito Yamao
Noriko Cauldron