公开(公告)号：US20230392226A1

公开(公告)日：2023-12-07

申请号：US18032298

申请日：2021-08-18

Applicant: JFE STEEL CORPORATION

Inventor： Shuhei OGAWA ,  Minoru TANAKA ,  Rinta SATO ,  Daisuke MIZUNO ,  Seiji NAKAJIMA

IPC: C21D9/46 ,  C21D8/02 ,  C22C18/04 ,  C21D7/02 ,  C22C38/60 ,  C22C38/32 ,  C22C38/28 ,  C22C38/26 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00

CPC classification number: C21D9/46 ,  C21D8/0205 ,  C22C18/04 ,  C21D7/02 ,  C22C38/60 ,  C22C38/32 ,  C22C38/28 ,  C22C38/26 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/002 ,  C22C38/001 ,  C21D8/0221 ,  C21D8/0247 ,  C21D8/0278 ,  C25D3/22

Abstract: A hot-pressed member, a steel sheet for hot pressing, and methods for producing the hot-pressed member and the steel sheet for hot pressing. The hot-pressed member includes a steel sheet and a Zn-based alloy coated layer disposed on at least one surface of the steel sheet. The Zn-based alloy coated layer includes a solid solution phase including Zn with the balance being Fe and incidental impurities, an intermetallic compound phase including Fe with the balance being Zn and incidental impurities, and an oxide layer including Zn. The oxide layer serves as an uppermost layer of the Zn-based alloy coated layer and splits the intermetallic compound phase. The split density in at least one cross-section of the oxide layer per unit cross-section is 10 split positions/mm or more.

公开(公告)号：US20240399439A1

公开(公告)日：2024-12-05

申请号：US18691456

申请日：2022-08-30

Applicant: JFE STEEL CORPORATION

Inventor： Minoru TANAKA ,  Rinta SATO ,  Ryoto NISHIIKE ,  Daisuke MIZUNO

IPC: B21D22/02 ,  C21D1/25 ,  C21D9/46 ,  C22C38/00 ,  C22C38/02 ,  C22C38/26 ,  C22C38/28 ,  C22C38/32 ,  C22C38/38 ,  C22C38/60 ,  C23C2/06 ,  C23C2/12 ,  C23C2/40 ,  C23C28/00

Abstract: A hot pressed member that has excellent appearance quality after coating and corrosion resistance at cut portion. The hot pressed member includes a steel sheet, a coated or plated layer containing FeAl, Fe2Al5, and Zn distributed over at least one side of the steel sheet, and a Zn-containing oxide layer distributed over the coated or plated layer. The solute Zn content in the Fe2Al5 is 10 mass % or more.

公开(公告)号：US20250108422A1

公开(公告)日：2025-04-03

申请号：US18726221

申请日：2022-11-17

Applicant: JFE STEEL CORPORATION

Inventor： Rinta SATO ,  Kazuhiko YAMAZAKI ,  Yoichi MAKIMIZU ,  Minoru TANAKA

IPC: B21D22/02 ,  C22C21/02 ,  C23C2/12 ,  C23C2/40

Abstract: A steel sheet for hot press forming that can reduce diffusible hydrogen content introduced in hot press forming without controlling the atmosphere dew point, and may be used to obtain a hot pressed member that has excellent post-coating corrosion resistance. The steel sheet includes a base steel sheet and a coated layer on both sides of the base steel sheet. The coated layer has a chemical composition containing Si: 7 mass % to 11 mass %, Mg: 0.6 mass % to 1.9 mass %, one or both of Ca and Sr: in total, 1.0% to 10% of Mg, and Fe: 0 mass % to 30 mass %, with the balance being Al and inevitable impurity. Concentration of Mg solute in Al phase in the coated layer is less than 1 mass %, and average thickness of the coated layer is 10 μm to 30 μm on each side of the base steel sheet.

公开(公告)号：US20250163558A1

公开(公告)日：2025-05-22

申请号：US18839142

申请日：2023-01-05

Applicant: JFE STEEL CORPORATION

Inventor： Rinta SATO ,  Yoichi MAKIMIZU ,  Ryoto NISHIIKE ,  Minoru TANAKA

IPC: C23C2/12 ,  C22C21/00 ,  C22C21/08 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/28 ,  C22C38/32 ,  C22C38/60 ,  C23C2/20 ,  C23C2/28

Abstract: Provided is a hot pressed member with excellent post-painting corrosion resistance and excellent corrosion resistance at lapped part. The hot pressed member includes: a steel material; an Al—Fe-based intermetallic compound layer with a thickness of 10 μm to 30 μm disposed on at least one side of the steel material; and Mg-containing oxide particles disposed on the Al—Fe-based intermetallic compound layer, wherein the Mg-containing oxide particles have an average particle size of 5.0 μm or less and a number density of 1000 particles/mm2 or more.

公开(公告)号：US20250129462A1

公开(公告)日：2025-04-24

申请号：US18690265

申请日：2022-08-30

Applicant: JFE STEEL CORPORATION

Inventor： Minoru TANAKA ,  Rinta SATO ,  Ryoto NISHIIKE ,  Daisuke MIZUNO

IPC: C23C2/12 ,  C23C2/26

Abstract: A hot pressed member that has excellent corrosion resistance after coating, in particular when a zirconium chemical conversion treatment is applied, and with reduced microcracks. The hot pressed member includes a steel sheet, a coated or plated layer containing FeAl, Fe2Al5, and Zn distributed over at least one side of the steel sheet, and a Zn-containing oxide layer distributed over the coated or plated layer. The solute Zn content in the FeAl is less than 10 mass %.

公开(公告)号：US20230095166A1

公开(公告)日：2023-03-30

申请号：US17905277

申请日：2020-10-29

Applicant: JFE STEEL CORPORATION

Inventor： Rinta SATO ,  Minoru TANAKA ,  Daisuke MIZUNO ,  Satoru ANDO

IPC: C21D8/02 ,  C22C38/06 ,  C22C38/00 ,  C21D9/46 ,  C23C30/00

Abstract: A hot pressed member disclosed herein includes: a base steel sheet; a Fe—Zn—Al—Mg-based alloy coated layer containing an α-Fe phase and a Γ phase and formed on at least one surface of the base steel sheet; and an oxide layer containing Zn, Al, and Mg and formed on the Fe—Zn—Al—Mg-based alloy coated layer, in which a ratio of IΓ/Iα is 0.5 or less when measured by X-ray diffraction using a Co-Kα (wavelength: 1.79021 Å) radiation source at an incident angle of 25°, where IF is an intensity of a diffraction peak of (411) plane of the Γ phase present in an angular range of 41.5°≤2θ≤43.0° and Iα is an intensity of a diffraction peak of (110) plane of the α-Fe phase present in an angular range of 51.0°≤2θ≤52.0°, and a sum of Al and Mg concentrations in the oxide layer is 28 atomic % or more.

公开(公告)号：US20220186339A1

公开(公告)日：2022-06-16

申请号：US17432218

申请日：2020-01-17

Applicant: JFE STEEL CORPORATION

Inventor： Katsutoshi TAKASHIMA ,  Minoru TANAKA ,  Yoshie OBATA ,  Michitaka SAKURAI

IPC: C21D9/48 ,  C21D8/04 ,  C21D6/00 ,  C22C38/60 ,  C22C38/54 ,  C22C38/50 ,  C22C38/48 ,  C22C38/46 ,  C22C38/44 ,  C22C38/42 ,  C22C38/06 ,  C22C38/58 ,  C22C38/00 ,  C22C38/02 ,  B32B15/01

Abstract: Provided is a hot-pressed member that combines both high strength of 1850 MPa or more in TS and excellent delayed fracture resistance. A hot-pressed member comprises: a predetermined chemical composition; a microstructure in which a prior austenite average grain size is 8 μm or less, a volume fraction of martensite is 95% or more, and a volume fraction of granular carbide of 0.1 μm or more in grain size is 0.10% to 4.0%; a Ni diffusion region of 2.0 μm or more in a depth direction in a surface layer; and a tensile strength of 1850 MPa or more.

公开(公告)号：US20180327884A1

公开(公告)日：2018-11-15

申请号：US15779157

申请日：2016-11-08

Applicant: JFE STEEL CORPORATION

Inventor： Mai AOYAMA ,  Minoru TANAKA ,  Yoshitsugu SUZUKI ,  Yoshiyasu KAWASAKI ,  Hideyuki TAKAHASHI

IPC: C21D9/46 ,  C21D8/02 ,  C21D6/00 ,  C22C38/38 ,  C22C38/28 ,  C22C38/16 ,  C22C38/14 ,  C22C38/12 ,  C22C38/08 ,  C22C38/06 ,  C22C38/04 ,  C22C38/00 ,  C22C38/60 ,  C22C38/02 ,  C23C2/02 ,  C23C2/06 ,  C23C2/40 ,  B32B15/01

CPC classification number: C21D9/46 ,  B32B15/013 ,  C21D1/185 ,  C21D1/76 ,  C21D6/004 ,  C21D6/005 ,  C21D6/008 ,  C21D8/0205 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0263 ,  C21D8/0273 ,  C21D8/0278 ,  C21D8/0463 ,  C21D8/0473 ,  C21D9/48 ,  C21D2211/001 ,  C21D2211/005 ,  C22C38/00 ,  C22C38/001 ,  C22C38/002 ,  C22C38/005 ,  C22C38/008 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/28 ,  C22C38/38 ,  C22C38/60 ,  C23C2/02 ,  C23C2/06 ,  C23C2/40

Abstract: A high-strength galvanized steel sheet and a method for producing the steel sheet. The steel sheet has a composition that includes C: 0.030% to 0.250%, Si: 0.01% to 3.00%, Mn: 2.00% to 10.00%, P: 0.001% to 0.100%, S: 0.0001% to 0.0200%, N: 0.0005% to 0.0100%, Ti: 0.005% to 0.200%, on a mass basis, and Fe and inevitable impurities. Additionally, the steel sheet has concentration of solute Mn at a depth of 5 μm or less from a surface of the steel sheet that is 1.50% by mass or less, and a value obtained by dividing the average mass percentage of Mn in retained austenite by the average mass percentage of Mn in ferrite is 2.0 or more.

公开(公告)号：US20230407449A1

公开(公告)日：2023-12-21

申请号：US18033101

申请日：2021-06-29

Applicant: JFE STEEL CORPORATION

Inventor： Rinta SATO ,  Minoru TANAKA ,  Daisuke MIZUNO ,  Ryoto NISHIIKE

IPC: C23C2/40 ,  C22C38/02 ,  C22C38/38 ,  C22C38/00 ,  C22C38/06 ,  C22C38/26 ,  C22C38/28 ,  C22C38/32 ,  C22C38/60 ,  B21D22/02 ,  C21D9/46 ,  C21D8/02 ,  C23C2/06 ,  C25D3/22 ,  C25D5/50

CPC classification number: C23C2/40 ,  C25D5/50 ,  C22C38/38 ,  C22C38/001 ,  C22C38/002 ,  C22C38/06 ,  C22C38/26 ,  C22C38/28 ,  C22C38/32 ,  C22C38/60 ,  B21D22/022 ,  C21D9/46 ,  C21D8/0247 ,  C23C2/06 ,  C25D3/22 ,  C22C38/02

Abstract: A hot-pressed member having excellent post-coating corrosion resistance and excellent resistance spot weldability, a method for manufacturing the hot-pressed member, and a steel sheet for hot pressing suitable for a hot-pressed member having excellent post-coating corrosion resistance and excellent resistance spot weldability. The hot-pressed member includes a Zn-based coated layer on a first side of a steel sheet, and a Zn-based coated layer on a second side of the steel sheet. A coating weight of Zn in the Zn-based coated layer on the first side of the steel sheet is 5 to 35 g/m2, and an average line roughness Ra of a surface of the Zn-based coated layer on the first side is less than or equal to 2.5 μm. The average line roughness Ra of a surface of the Zn-based coated layer on the second side of the steel sheet is greater than or equal to 3.5 μm.

公开(公告)号：US20220177992A1

公开(公告)日：2022-06-09

申请号：US17437357

申请日：2020-02-13

Applicant: JFE STEEL CORPORATION

Inventor： Yoshie OBATA ,  Katsutoshi TAKASHIMA ,  Minoru TANAKA ,  Yoshiko NAKAHARA

IPC: C21D9/46 ,  B21D22/02 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/14 ,  C22C38/12 ,  C22C38/60 ,  C23C2/06 ,  C23C2/12 ,  C23C2/40 ,  C23G1/00 ,  C21D8/02 ,  B21C47/02

Abstract: A hot press member includes excellent indentation peel strength which has a tensile strength of 1780 MPa or more. A plating layer has at a surface thereof a 10-point average roughness Rzjis of 25 μm or less, and a steel sheet contains, in mass %, not less than 0.25% but less than 0.50% of C, 1.5% or less of Si, 1.1-2.4% of Mn, 0.05% or less of P, 0.005% or less of S, 0.01-0.50% of Al, 0.010% or less of N, 0.001-0.020% of Sb, 0.005-0.15% of Nb, and 0.005-0.15% of Ti, the balance being Fe and incidental impurities. The average crystal grain size of prior austenite is 7 μm or less and the volume proportion of martensite is 90% or more, within 50 μm in the thickness direction from the surface of the steel sheet excluding the plating layer.