公开(公告)号：US20240150864A1

公开(公告)日：2024-05-09

申请号：US18548970

申请日：2022-02-25

Applicant: JFE STEEL CORPORATION

Inventor： Satoshi MAEDA ,  Nao KAWABE ,  Hiromi YOSHITOMI

IPC: C21D9/46 ,  C21D6/00 ,  C21D8/02 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/26 ,  C22C38/28 ,  C22C38/38 ,  C22C38/60 ,  C23C2/06 ,  C23C2/28

CPC classification number: C21D9/46 ,  C21D6/001 ,  C21D6/002 ,  C21D6/005 ,  C21D6/008 ,  C21D8/0205 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0263 ,  C21D8/0278 ,  C22C38/001 ,  C22C38/002 ,  C22C38/008 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/26 ,  C22C38/28 ,  C22C38/38 ,  C22C38/60 ,  C23C2/06 ,  C23C2/285

Abstract: To provide a galvanized steel sheet having high strength; specifically, with a tensile strength of 1160 MPa or more and excellent resistance spot weldability. A chemical composition of a base steel sheet contains one or more of Ti, Nb, V, and Zr: 0.02% or more and 0.20% or less in total, and an amount of diffusible hydrogen in a zinc or zinc alloy coating layer is 0.40 mass ppm or less.

公开(公告)号：US20190040511A1

公开(公告)日：2019-02-07

申请号：US16072904

申请日：2017-01-26

Applicant: JFE STEEL CORPORATION

Inventor： Hiroshi HASEGAWA ,  Yoshimasa FUNAKAWA ,  Hiromi YOSHITOMI ,  Yoichi MAKIMIZU ,  Yoshitsugu SUZUKI ,  Gentaro TAKEDA ,  Yoshikazu SUZUKI ,  Yoshimasa HIMEI

IPC: C23C2/02 ,  C22C38/60 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C21D9/46 ,  C23C2/06 ,  C23C2/26 ,  C23C2/40

Abstract: A high-strength galvanized steel sheet having improved post-work impact resistance, a method for producing the high-strength galvanized steel sheet, and a high-strength member produced using the steel sheet. The high-strength galvanized steel sheet includes a steel sheet having a microstructure including ferrite and carbide-free bainite, martensite and carbide-containing bainite, and retained austenite, the total area fraction of ferrite and carbide-free bainite being 0% to 55%, the total area fraction of martensite and carbide-containing bainite being 45% to 100%, and the area fraction of retained austenite being 0% to 5%. Additionally, a galvanizing layer is disposed on the steel sheet. The density of gaps that cut across the entire thickness of the galvanizing layer in a cross section of the galvanizing layer, which is taken in the thickness direction so as to be perpendicular to the rolling direction, is 10 gaps/mm or more.

公开(公告)号：US20210130920A1

公开(公告)日：2021-05-06

申请号：US17041680

申请日：2019-03-29

Applicant: JFE STEEL CORPORATION

Inventor： Hiromi YOSHITOMI ,  Tatsuya NAKAGAITO ,  Masaki KOBA ,  Yoshitsugu SUZUKI

IPC: C21D9/46 ,  C21D8/02 ,  C21D6/00 ,  C22C38/14 ,  C22C38/12 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  C23C2/06 ,  C23C2/40 ,  C23C2/02 ,  B32B15/01

Abstract: A high-strength galvanized steel sheet of the present invention includes a steel sheet having a chemical composition containing a predetermined component element, and a steel structure in which an average grain size of inclusions containing at least one of Al, Si, Mg, and Ca and existing in an area extending from a surface to a position of ⅓ of a sheet thickness is 50 μm or less, and an average nearest distance between ones of the inclusions is 20 μm or more; and a galvanized layer provided on a surface of the steel sheet and having a coating weight per one surface of 20 g/m2 or more and 120 g/m2 or less, in which an amount of diffusible hydrogen contained in the steel is less than 0.25 mass ppm, and a tensile strength is 1100 MPa or more.

公开(公告)号：US20240150882A1

公开(公告)日：2024-05-09

申请号：US18548927

申请日：2022-02-25

Applicant: JFE STEEL CORPORATION

Inventor： Satoshi MAEDA ,  Hiromi YOSHITOMI ,  Masaki KOBA ,  Nao KAWABE ,  Tatsuya NAKAGAITO ,  Katsuya HOSHINO ,  Hiroshi MATSUDA

IPC: C22C38/60 ,  C21D6/00 ,  C21D8/02 ,  C21D9/46 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/38 ,  C23C2/06 ,  C23C2/28

CPC classification number: C22C38/60 ,  C21D6/001 ,  C21D6/002 ,  C21D6/005 ,  C21D6/008 ,  C21D8/0205 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0263 ,  C21D8/0278 ,  C21D9/46 ,  C22C38/001 ,  C22C38/002 ,  C22C38/008 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/38 ,  C23C2/06 ,  C23C2/285

Abstract: To provide a galvanized steel sheet having high strength, specifically, a tensile strength of 1,150 MPa or more, and excellent resistance spot weldability, a base steel sheet has a defined chemical composition, an amount of diffusible hydrogen in the base steel sheet is 0.20 mass ppm or less, and surface roughness Ra of the galvanized steel sheet is 0.6 μm or less.