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:
Jun. 08, 2021
Filed:
Sep. 28, 2018
Nippon Steel & Sumitomo Metal Corporation, Tokyo, JP;
Chisato Wakabayashi, Tokyo, JP;
Fuminori Watanabe, Tokyo, JP;
Seiji Furusako, Tokyo, JP;
Yasunobu Miyazaki, Tokyo, JP;
Hiroyuki Kawata, Tokyo, JP;
Tohru Okada, Tokyo, JP;
Hideki Hamatani, Tokyo, JP;
NIPPON STEEL CORPORATION, Tokyo, JP;
Abstract
By obtaining a spot-welded joint being a spot-welded joint formed by overlapping a plurality of pieces of steel plates (A,B) and performing spot welding on the steel plates, including a high-strength steel plate whose tensile strength is 750 (MPa) to 2500 (MPa), being at least one piece of steel plate out of the plurality of pieces of steel plates, in which a carbon equivalent Ceq of the high-strength steel plate is 0.20 mass % to 0.55 mass %, and ten or more of iron-based carbides in each of which a length of a longest portion is 0.1 (μm) or more exist in a square regionwithin a heat-affected zoneof a cross section that passes through a center of a welding mark, and is cut along a plate thickness direction of the steel plates (A,B), a cross tensile strength of the spot-welded joint to be formed is improved.