Title:
COLD-ROLLED STEEL SHEET AND HOT-DIP GALVANIZED COLD-ROLLED STEEL SHEET
Document Type and Number:
WIPO Patent Application WO/2018/179386
Kind Code:
A1
Abstract:
A cold-rolled steel sheet with a tensile strength of at least 980 MPa has a prescribed chemical composition. The microstructure, in area%, is ferrite: 1-29%, retained austenite: 5-20%, martensite: less than 10%, pearlite: less than 5%, and balance: bainite and/or tempered martensite. The total length of interfaces, where ferrite is in contact with martensite or with retained austenite having an equivalent circular radius of at least 1 µm, is 100 µm or less per 1000 µm2. Said cold-rolled steel sheet has excellent workability and low-temperature toughness, especially low-temperature toughness after introducing plastic deformation.
Inventors:
YOKOYAMA TAKAFUMI (JP)
OKAMOTO RIKI (JP)
YAMAGUCHI YUJI (JP)
SHIOKAWA KAZUKI (JP)
NAKAHIRA YUICHI (JP)
KAWATA HIROYUKI (JP)
OKAMOTO RIKI (JP)
YAMAGUCHI YUJI (JP)
SHIOKAWA KAZUKI (JP)
NAKAHIRA YUICHI (JP)
KAWATA HIROYUKI (JP)
Application Number:
PCT/JP2017/013736
Publication Date:
October 04, 2018
Filing Date:
March 31, 2017
Export Citation:
Assignee:
NIPPON STEEL & SUMITOMO METAL CORP (JP)
International Classes:
C22C38/00; C23C2/06; C21D9/46
Domestic Patent References:
WO2017002883A1 | 2017-01-05 | |||
WO2013047830A1 | 2013-04-04 | |||
WO2013151238A1 | 2013-10-10 |
Foreign References:
JP2014034716A | 2014-02-24 | |||
JP2009108343A | 2009-05-21 | |||
JP2004068050A | 2004-03-04 | |||
JP2006104532A | 2006-04-20 | |||
JP2007262494A | 2007-10-11 | |||
JP2015086468A | 2015-05-07 | |||
JP2015200006A | 2015-11-12 | |||
JP2014034716A | 2014-02-24 | |||
JP2011132602A | 2011-07-07 | |||
JP2015025208A | 2015-02-05 | |||
JP2014133944A | 2014-07-24 |
Other References:
See also references of EP 3604582A4
Attorney, Agent or Firm:
BRIGHTAS IP ATTORNEYS (JP)
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