公开(公告)号：US20220177034A1

公开(公告)日：2022-06-09

申请号：US17432796

申请日：2020-02-18

Applicant: JFE STEEL CORPORATION

Inventor： Tomohiro SAKAIDANI ,  Kentaro SATO ,  Takayuki FUTATSUKA

IPC: B62D21/15 ,  B62D27/02

Abstract: A collision resistance performance of a structural member is effectively improved while suppressing an unnecessary increase in mass of the structural member. The structural member includes a hollow member and a tension member. The hollow member forms a closed cross-sectional shape by a top sheet portion, a pair of sidewall portions each continuous to each side of the top sheet portion in a width direction, and a bottom sheet portion arranged to face the top sheet portion. The tension member is formed by a metal sheet extending along the width direction of the top sheet portion and being thinner than the sheet thickness of the hollow member, and connects inner surfaces of the pair of sidewall portions facing each other to each other to restrain the distance between the pair of sidewall portions from increasing.

公开(公告)号：US20220018747A1

公开(公告)日：2022-01-20

申请号：US17311236

申请日：2019-12-16

Applicant: JFE STEEL CORPORATION

Inventor： Kentaro SATO ,  Takayuki FUTATSUKA ,  Tomohiro SAKAIDANI ,  Shinsuke KOMINE ,  Yoshiyasu KAWASAKI

IPC: G01N3/20 ,  G01N3/24 ,  G01N3/307

Abstract: A collision performance evaluation test with few variations in test results with high accuracy in which a complicated phenomenon that actually occurs can be reproduced in a simple manner by considering the history of deformation in both the press forming and a collision. A collision performance evaluation test method for a metal sheet material for an automobile body is characterized in that a press working apparatus first forms a flat test specimen made of a metal sheet material to be tested into a V shape by primary bending, a bending test apparatus then deforms, by secondary bending, the test specimen formed by the primary bending in a direction intersecting with the primary bending direction, and a bending load and a bending stroke for the test specimen during the secondary bending deformation are recorded and evaluated.

公开(公告)号：US20210130919A1

公开(公告)日：2021-05-06

申请号：US16762501

申请日：2018-11-07

Applicant: JFE STEEL CORPORATION

Inventor： Katsutoshi TAKASHIMA ,  Takayuki FUTATSUKA ,  Kentaro SATO ,  Shimpei YOSHIOKA ,  Yoshihiko ONO ,  Yoshimasa FUNAKAWA

IPC: C21D9/46 ,  B32B15/01 ,  C21D8/02 ,  C21D6/00 ,  C22C38/58 ,  C22C38/54 ,  C22C38/52 ,  C22C38/50 ,  C22C38/48 ,  C22C38/46 ,  C22C38/44 ,  C22C38/42 ,  C22C38/06 ,  C22C38/02 ,  C22C38/00 ,  C22C38/60

Abstract: Disclosed is a hot-pressed steel sheet member having a tensile strength of 1780 MPa or more and excellent bending collapsibility. The hot-pressed steel sheet member includes: a specific chemical composition; a microstructure in which an average grain size of prior austenite grains is 8 μm or less, a volume fraction of martensite is 90% or more, and a solute C content is 25% or less of a total C content; and a tensile strength of 1780 MPa or more.

公开(公告)号：US20200332382A1

公开(公告)日：2020-10-22

申请号：US16754135

申请日：2018-11-07

Applicant: JFE STEEL CORPORATION

Inventor： Katsutoshi TAKASHIMA ,  Takayuki FUTATSUKA ,  Kentaro SATO ,  Shimpei YOSHIOKA ,  Yoshihiko ONO ,  Yoshimasa FUNAKAWA

IPC: C21D9/46 ,  C21D8/02 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/10 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/32 ,  C23C2/06 ,  C23C2/12

Abstract: Disclosed is a hot-pressed steel sheet member having a tensile strength of 1780 MPa or more and excellent bending collapsibility. The hot-pressed steel sheet member has: a specific chemical composition where a ratio of a C content in mass % to a Nb content in mass %, C/Nb, is from 22 to 100; a microstructure in which an average grain size of prior austenite grains is 8 μm or less, a volume fraction of martensite is 90% or more, and a solute C content is 25% or less of a total C content; and a tensile strength of 1780 MPa or more.