Title:
GALVANIZED STEEL SHEET AND PRODUCTION METHOD THEREFOR
Document Type and Number:
WIPO Patent Application WO/2019/212045
Kind Code:
A1
Abstract:
This galvanized steel sheet comprises: a steel sheet having a prescribed chemical composition; and a galvanized layer. The steel sheet has a steel composition in a range of 1/8–3/8 thickness, centered on ¼ thickness from the surface, and contains: 0–10 vol% of ferrite, 0–30 vol% of bainite, at least 50 vol% of tempered martensite, 0–10 vol% fresh martensite, more than 10 vol% and no more than 30 vol% residual austenite, and 0–5 vol% pearlite. The galvanized steel sheet: has, per steel plate mass, no more than 0.40 ppm hydrogen released when the steel plate is heated from room temperature to 200°C after the galvanized layer is removed; has a tensile strength of at least 1,470 MPa, and does not crack in a U-bending test during which a stress equivalent to 1,000 MPa is applied for 24 hours.
Inventors:
YOKOYAMA TAKAFUMI (JP)
HAYASHI KUNIO (JP)
NAKATA MASAHIRO (JP)
YAMAGUCHI YUJI (JP)
UCHIDA SATOSHI (JP)
HAYASHI KUNIO (JP)
NAKATA MASAHIRO (JP)
YAMAGUCHI YUJI (JP)
UCHIDA SATOSHI (JP)
Application Number:
PCT/JP2019/017949
Publication Date:
November 07, 2019
Filing Date:
April 26, 2019
Export Citation:
Assignee:
NIPPON STEEL CORP (JP)
International Classes:
C22C38/00; C21D9/46; C22C38/60; C22C18/04
Domestic Patent References:
| WO2018055695A1 | 2018-03-29 | |||
| WO2016199922A1 | 2016-12-15 | |||
| WO2016129550A1 | 2016-08-18 | |||
| WO2015151428A1 | 2015-10-08 | |||
| WO2014112594A1 | 2014-07-24 | |||
| WO2009096595A1 | 2009-08-06 |
Foreign References:
| JP2017002384A | 2017-01-05 | |||
| JP2006207020A | 2006-08-10 |
Attorney, Agent or Firm:
TANAI Sumio et al. (JP)
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