Title:
HIGH STRENGTH HOT-DIP GALVANIZED STEEL SHEET EXCELLENT IN PROCESSABILITY AND METHOD FOR MANUFACTURING THE SAME
Document Type and Number:
Japanese Patent JP2015113504
Kind Code:
A
Abstract:
PROBLEM TO BE SOLVED: To provide a high strength hot-dip galvanized steel sheet that is excellent in ductility and stretch flanging property and has uniform mechanical characteristics in a sheet thickness direction, particularly uniform hardness.SOLUTION: A high strength hot-dip galvanized steel sheet has a component composition containing, by mass%, 0.05-0.3% of C, 0.01-2.5% of Si, 0.5-3.5% of Mn, 0.003-0.100% of P, 0.02% or less of S and 0.010-1.5% of Al, having a total amount of Si and Al of 0.5-2.5%, and the balance Fe with inevitable impurities. The steel sheet has a structure comprising, by an area ratio based on the total structure, 20% or more of a ferrite phase, 10% or less of a martensite phase (inclusive of 0%) and 10-60% of a tempered martensite phase and comprising, by a volume ratio based on the total structure, 3-10% of a retained austenite phase. The variation ΔHv in hardness in the sheet thickness direction is 20 or less.
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Inventors:
NAKAMURA NOBUYUKI
SAKURAI MICHITAKA
SUZUKI KATSUICHI
IKEHARA YUYA
HARAI YOSUKE
SAKURAI MICHITAKA
SUZUKI KATSUICHI
IKEHARA YUYA
HARAI YOSUKE
Application Number:
JP2013257363A
Publication Date:
June 22, 2015
Filing Date:
December 12, 2013
Export Citation:
Assignee:
JFE STEEL CORP
International Classes:
C22C38/00; C21D9/46; C22C38/06; C22C38/58
Domestic Patent References:
| JP2012229466A | 2012-11-22 | |||
| JP2008291304A | 2008-12-04 | |||
| JP2010275627A | 2010-12-09 | |||
| JP2009203548A | 2009-09-10 |
Attorney, Agent or Firm:
Kenji Sugimura
Keisuke Kawahara
Keisuke Kawahara