Title:
WELDED JOINT AND AUTOMOBILE COMPONENT
Document Type and Number:
WIPO Patent Application WO/2022/149511
Kind Code:
A1
Abstract:
The technique of the present disclosure is for suppressing liquid metal embrittlement (LME) cracking and improving corrosion resistance of a welded joint that is produced by spot-welding a first steel plate and a second steel plate together. In the case of the welded joint of the present disclosure: a first plating layer is provided on a surface of the first steel plate facing the second steel plate; and no plating layer is provided on a surface of the second steel plate facing the first steel plate, or a second plating layer is provided thereon. A boundary plating layer is provided between the first steel plate and the second steel plate and in a 0.5 mm region extending from an end of a corona bond of the spot-welded part toward the outside of the spot-welded part, and a Zn-penetration part is present in the first steel plate and/or the second steel plate adjacent to the boundary plating layer. The Zn-penetration part develops from the boundary plating layer along a steel grain boundary, wherein at the tip position of the Zn-penetration part where the concentration of Zn is 0.1 mass%, the concentration of Mg is 0.20 mass% or lower. The first plating layer and the second plating layer satisfy predetermined relation I.
Inventors:
MITSUNOBU TAKUYA (JP)
TAKEBAYASHI HIROSHI (JP)
TAKAHASHI TAKEHIRO (JP)
TAKEBAYASHI HIROSHI (JP)
TAKAHASHI TAKEHIRO (JP)
Application Number:
PCT/JP2021/048411
Publication Date:
July 14, 2022
Filing Date:
December 24, 2021
Export Citation:
Assignee:
NIPPON STEEL CORP (JP)
International Classes:
C21D9/46; B23K11/16; C22C18/00; C22C18/04; C22C21/00; C22C21/06; C22C21/10; C22C23/00; C22C23/02; C22C23/04; C22C38/00; C22C38/60; C23C2/06
Domestic Patent References:
| WO2019116531A1 | 2019-06-20 | |||
| WO2020213686A1 | 2020-10-22 |
Foreign References:
| JP2008038168A | 2008-02-21 | |||
| JP2020179413A | 2020-11-05 | |||
| JP2017047045A | 2017-03-09 | |||
| JP2005103608A | 2005-04-21 |
Attorney, Agent or Firm:
AOKI, Atsushi et al. (JP)
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