Title:
STEEL SHEET AND PLATED STEEL SHEET
Document Type and Number:
WIPO Patent Application WO/2018/138887
Kind Code:
A1
Abstract:
A steel sheet that has a specified chemical composition and has a microstructure in which, when a region surrounded by grain boundaries of at least 5.0° as measured by EBSD analysis is a single crystal grain, the average image quality value within the crystal grain multiplied by 10-3 is the K-value, the average crystal grain orientation spread (°) within the crystal grain is the Y-value, metal phases in which the K-value is less than 4.000 are metal phase 1, metal phases in which the K-value is at least 4.000 and the Y-value is 0.5-1.0 are metal phase 2, metal phases in which the K-value is at least 4.000 and the Y-value is less than 0.5 are metal phase 3, and metal phases that do not belong in any of metal phases 1-3 are metal phase 4, in area%: 1.0% to less than 35.0% is metal phase 1; 30.0% to 80.0% is metal phase 2; 5.0% to 50.0% is metal phase 3; and 5.0% or less is metal phase 4. Said steel sheet has high strength with a tensile strength of at least 590 MPa (even better, at least 780 MPa) and excellent hole expandability.
Inventors:
TODA YURI (JP)
AZUMA MASAFUMI (JP)
UENISHI AKIHIRO (JP)
SAKURADA EISAKU (JP)
YOKOI TATSUO (JP)
SHIGESATO GENICHI (JP)
AZUMA MASAFUMI (JP)
UENISHI AKIHIRO (JP)
SAKURADA EISAKU (JP)
YOKOI TATSUO (JP)
SHIGESATO GENICHI (JP)
Application Number:
PCT/JP2017/003023
Publication Date:
August 02, 2018
Filing Date:
January 27, 2017
Export Citation:
Assignee:
NIPPON STEEL & SUMITOMO METAL CORP (JP)
International Classes:
C22C38/00; B21B1/02; C21D9/46; C22C38/58
Domestic Patent References:
| WO2016132549A1 | 2016-08-25 | |||
| WO2016125463A1 | 2016-08-11 | |||
| WO2014185405A1 | 2014-11-20 | |||
| WO2016132549A1 | 2016-08-25 | |||
| WO2016133222A1 | 2016-08-25 |
Foreign References:
| JPH08302426A | 1996-11-19 | |||
| JP2006274318A | 2006-10-12 | |||
| JP2013181208A | 2013-09-12 | |||
| JP2011225941A | 2011-11-10 | |||
| JP2012026032A | 2012-02-09 | |||
| JP2011195956A | 2011-10-06 | |||
| JP2014141703A | 2014-08-07 | |||
| JP2011184788A | 2011-09-22 |
Other References:
YURI KITAJIMA ET AL.: "Denshi Channeling Contrast Zo o Mochiita Ferrite to Granular Bainite no Shikibetsu", CURRENT ADVANCES IN MATERIALS AND PROCESSES, vol. 26, no. 2, 1 September 2013 (2013-09-01), pages 896, XP009515411
KATO ET AL., YAWATA TECHNICAL REPORT, vol. 312, 1984, pages 41
See also references of EP 3575426A4
KATO ET AL., YAWATA TECHNICAL REPORT, vol. 312, 1984, pages 41
See also references of EP 3575426A4
Attorney, Agent or Firm:
BRIGHTAS IP ATTORNEYS (JP)
Download PDF:
Previous Patent: LASER DEVICE AND EXTREME ULTRAVIOLET LIGHT GENERATION SYSTEM
Next Patent: LIQUID CRYSTAL DISPLAY DEVICE
Next Patent: LIQUID CRYSTAL DISPLAY DEVICE