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:
Oct. 31, 2023
Filed:
Oct. 09, 2019
Nippon Steel Corporation, Tokyo, JP;
Yuri Toda, Tokyo, JP;
Hiroaki Kubota, Tokyo, JP;
Hiroyuki Kawata, Tokyo, JP;
Daisuke Maeda, Tokyo, JP;
NIPPON STEEL CORPORATION, Tokyo, JP;
Abstract
In a frame member, the hardness of a sheet-thickness-direction central section in a portion where a softening layer is provided is greater than or equal to 400 Hv, the softening layer has hardness smaller by at least 10 Hv than the hardness of the sheet-thickness-direction central section in the portion where the softening layer is provided, the thickness of the softening layer is greater than or equal to 2% of the sheet thickness but smaller than 20% of the sheet thickness, the hardness of the softening layer at the surface is greater than or equal to 0.5 times the hardness of the sheet-thickness-direction central section but smaller than 0.9 times the hardness of the sheet-thickness-direction central section, the softening layer has a first hardness changing area and a second hardness changing area, an absolute value ΔHv1 of a change in hardness of the first hardness changing area in the sheet thickness direction is greater than an absolute value ΔHv2 of a change in hardness of the second hardness changing area in the sheet thickness direction, and R/t≤2.5 is satisfied, where R represents the bending radius of the corner section, and t represents the sheet thickness of the corner section.