公开(公告)号：US20250065387A1

公开(公告)日：2025-02-27

申请号：US18688955

申请日：2022-09-01

Applicant: JFE STEEL CORPORATION

Inventor： Yuichi MATSUKI ,  Toyohisa SHINMIYA ,  Kinya NAKAGAWA ,  Yuji YAMASAKI

IPC: B21D5/08 ,  B21B15/00 ,  B21D1/02

Abstract: A method for improving the delayed fracture characteristics of a metal sheet made of a high-strength steel sheet to suppress delayed fracture from a sheared end face after forming by a simple method. A method for improving delayed fracture characteristics of a metal sheet, the metal sheet having a sheared end face on at least a part of a sheet end portion and being made of a high-strength steel sheet. Plastic deformation is imparted to at least a part of the sheared end face of the metal sheet.

公开(公告)号：US20240044760A1

公开(公告)日：2024-02-08

申请号：US18255932

申请日：2021-07-29

Applicant: JFE STEEL CORPORATION

Inventor： Yuichi MATSUKI ,  Toyohisa SHINMIYA ,  Kinya NAKAGAWA ,  Yuji YAMASAKI

IPC: G01N3/20

CPC classification number: G01N3/20 ,  G01N2203/0064 ,  G01N2203/0067 ,  G01N2203/0236 ,  G01N2203/0282

Abstract: To further enhance the evaluation accuracy of a delayed fracture. Focusing on the fact that a calculated stress value serving as the reference for the occurrence of the delayed fracture changes depending on analysis conditions of a forming analysis, a value obtained by changing a stress value serving as the reference for the occurrence of the delayed fracture according to the analysis conditions for analyzing an intended formed article (article for practical use) is used as the reference for evaluating the delayed fracture. For example, analysis conditions of a forming analysis in an evaluation test of the delayed fracture are matched with analysis conditions of a forming analysis of an article for practical use represented by an actual automobile component.

公开(公告)号：US20230264248A1

公开(公告)日：2023-08-24

申请号：US18010126

申请日：2021-06-08

Applicant: JFE STEEL CORPORATION

Inventor： Yuichi MATSUKI ,  Kinya NAKAGAWA ,  Toyohisa SHINMIYA ,  Yuji YAMASAKI

IPC: B21D28/16 ,  B21D28/14

CPC classification number: B21D28/16 ,  B21D28/14

Abstract: A shearing work technology of metal sheets, such as high-strength steel sheets, is excellent in stretch flange crack resistance and delayed fracture resistance of the sheared end surface. A metal sheet shearing work method including: applying double shearing work to an end portion of at least one part of the metal sheet; and forming a first area having a cutting margin of a second shearing work of 5 mm or less in first cutting in the double shearing work. Second cutting in the double shearing work is carried out in a state where the movement on an end portion side of the first area is restrained. For example, by providing projection areas continuous to the first area and restraining the projection areas, the movement on the end portion side of the first area is restrained.