The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 09, 2024
Filed:
May. 24, 2019
Nippon Steel Corporation, Tokyo, JP;
Tasuku Zeniya, Tokyo, JP;
Satoshi Hirose, Tokyo, JP;
Atsuo Koga, Tokyo, JP;
Koichi Hamada, Tokyo, JP;
Masanori Yasuyama, Tokyo, JP;
NIPPON STEEL CORPORATION, Tokyo, JP;
Abstract
This spot welded joint includes a first steel sheet having tensile strength of 1100 MPa or higher and hard martensitic structure as main structure, a second steel sheet stacked on the first steel sheet, a nugget having diameter D at an interface between the first and second steel sheets and formed between the first and second steel sheets, and a hardness control region occupying, in a cross section of the first steel sheet in sheet thickness direction that passes a nugget center, a region that is the first steel sheet in sheet thickness direction and is from 0.5×D to 1.0×D from the nugget center in sheet surface direction and in which difference between maximum value and minimum value in hardness in the region is 80 HV or less, and the maximum hardness value in the region is lower than the maximum hardness value of the first steel sheet.