Title:
SPOT WELDED JOINT AND METHOD FOR MANUFACTURING SPOT WELDED JOINT
Document Type and Number:
WIPO Patent Application WO/2022/210749
Kind Code:
A1
Abstract:
Provided is a spot welded joint, in which, in a cross section in a plate thickness direction of a plate set in which two or more steel plates are stacked, the steel plates including at least one steel sheet having a C content of 0.280-0.700 mass%: the average of the short diameters of prior austenite particles, the long diameters thereof, and ratios (long diameter/short diameter) of the long diameters to the short diameters is in the range 1.0-1.5 in a melting boundary region, which is a region extending 1 mm inward from a melting boundary at a nugget end section; and the number density of an iron carbide having, at the melting boundary region, an average circle equivalent diameter of 30 nm or greater is 3.0×106×C content (mass%) or greater per 1 mm2. The plate set in which the C content of at least one steel plate is 0.280-0.700 in terms of mass% is subjected to spot welding under specific conditions, and subsequently, tempering thereof is performed under specific conditions.
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Inventors:
YOSHINAGA CHISATO (JP)
YASUYAMA MASANORI (JP)
KAWAI AOSHI (JP)
KAYANO MATSUO (JP)
YASUYAMA MASANORI (JP)
KAWAI AOSHI (JP)
KAYANO MATSUO (JP)
Application Number:
PCT/JP2022/015612
Publication Date:
October 06, 2022
Filing Date:
March 29, 2022
Export Citation:
Assignee:
NIPPON STEEL CORP (JP)
International Classes:
C22C38/00; B23K11/11; B23K11/16; B23K11/24; B23K31/00; C22C38/60
Domestic Patent References:
| WO2011025015A1 | 2011-03-03 |
Foreign References:
| JP2018162477A | 2018-10-18 | |||
| JP2013086125A | 2013-05-13 |
Attorney, Agent or Firm:
TAIYO, NAKAJIMA & KATO (JP)
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