公开(公告)号：US20230153976A1

公开(公告)日：2023-05-18

申请号：US17915126

申请日：2021-03-08

Applicant: JFE Steel Corporation

Inventor： Naoya Kiyokane ,  Yoshie Obata ,  Shin Ishikawa ,  Takako Yamashita ,  Takeshi Nishiyama

IPC: G06T7/00 ,  G01N33/204 ,  G01N1/32 ,  G06V10/764 ,  G06V10/10 ,  G06V10/98 ,  H04N23/60 ,  G06V20/70

CPC classification number: G06T7/0004 ,  G01N33/204 ,  G01N1/32 ,  G06V10/764 ,  G06V10/10 ,  G06V10/993 ,  H04N23/64 ,  G06V20/70 ,  G06T2207/30136 ,  G06T2207/20084 ,  G06T2207/30168 ,  G06T2207/10056

Abstract: A photographing condition determining method includes: photographing a part of a metal structure of a metal material subjected to predetermined sample preparation under a predetermined photographing condition; assigning, to pixels corresponding to one or a plurality of predetermined phases of the metal structure, labels of respective phases for a photographed image; calculating one or more feature values for a pixel to which a label of one of the assigned phases; classifying the phases of the metal structure of the image by inputting a calculated feature value to a model, which has been learned in advance using feature values assigned with labels of respective phases as input and labels of the respective phases as output, and acquiring a label of a phase of a pixel corresponding to the input feature value; and determining a photographing condition when other parts of the metal structure are photographed based on a classification result.

公开(公告)号：US12215405B2

公开(公告)日：2025-02-04

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 ,  B32B15/01 ,  C21D6/00 ,  C21D8/04 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C22C38/54 ,  C22C38/58 ,  C22C38/60 ,  C21D9/00 ,  C23C2/06 ,  C23C2/40

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：US12163202B2

公开(公告)日：2024-12-10

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 ,  B21C47/02 ,  B21D22/02 ,  C21D8/02 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12 ,  C22C38/14 ,  C22C38/60 ,  C23C2/02 ,  C23C2/06 ,  C23C2/12 ,  C23C2/28 ,  C23C2/40 ,  C23G1/00

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.

公开(公告)号：US12106466B2

公开(公告)日：2024-10-01

申请号：US17915126

申请日：2021-03-08

Applicant: JFE Steel Corporation

Inventor： Naoya Kiyokane ,  Yoshie Obata ,  Shin Ishikawa ,  Takako Yamashita ,  Takeshi Nishiyama

IPC: G01N1/32 ,  G01N33/204 ,  G06T7/00 ,  G06V10/10 ,  G06V10/764 ,  G06V10/98 ,  G06V20/70 ,  H04N23/60

CPC classification number: G06T7/0004 ,  G01N1/32 ,  G01N33/204 ,  G06V10/10 ,  G06V10/764 ,  G06V10/993 ,  G06V20/70 ,  H04N23/64 ,  G06T2207/10056 ,  G06T2207/20084 ,  G06T2207/30136 ,  G06T2207/30168

Abstract: A photographing condition determining method includes: photographing a part of a metal structure of a metal material subjected to predetermined sample preparation under a predetermined photographing condition; assigning, to pixels corresponding to one or a plurality of predetermined phases of the metal structure, labels of respective phases for a photographed image; calculating one or more feature values for a pixel to which a label of one of the assigned phases; classifying the phases of the metal structure of the image by inputting a calculated feature value to a model, which has been learned in advance using feature values assigned with labels of respective phases as input and labels of the respective phases as output, and acquiring a label of a phase of a pixel corresponding to the input feature value; and determining a photographing condition when other parts of the metal structure are photographed based on a classification result.

公开(公告)号：US20220064752A1

公开(公告)日：2022-03-03

申请号：US17420216

申请日：2019-12-23

Applicant: JFE Steel Corporation

Inventor： Yoshie Obata ,  Katsutoshi Takashima ,  Takeshi Yokota

IPC: C21D9/46 ,  C21D8/02 ,  C21D6/00 ,  C22C38/60 ,  C22C38/38 ,  C22C38/28 ,  C22C38/26 ,  C22C38/32 ,  C22C38/16 ,  C22C38/14 ,  C22C38/12 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  C23C2/06 ,  C23C2/40 ,  C22C18/04 ,  C23C2/28

Abstract: A high-strength cold rolled steel sheet has a specific composition and a steel structure that is, by volume %, 10%-70% ferrite, 1%-10% retained austenite, 10%-60% bainite, and 2%-50% martensite, the average crystal grain size of the ferrite being no more than 6.0 μm, the average crystal grain size of the retained austenite being no more than 4.0 μm, the average crystal grain size of the bainite being no more than 6.0 μm, and the average crystal grain size of the martensite being no more than 4.0 μm. The concentration ratio of the average concentration of Si to a depth of 10 μm from the surface of the high-strength cold-rolled steel sheet to the average concentration of Si throughout the high-strength cold-rolled steel sheet is, by mass ratio, greater than 1.00 but less than 1.30.

公开(公告)号：US11136644B2

公开(公告)日：2021-10-05

申请号：US16325299

申请日：2017-08-29

Applicant: JFE STEEL CORPORATION

Inventor： Yoshie Obata ,  Katsutoshi Takashima ,  Takashi Kobayashi ,  Hiroshi Matsuda

IPC: C21D9/46 ,  C21D8/02 ,  C21D6/00 ,  C22C38/38 ,  C22C38/32 ,  C22C38/28 ,  C22C38/26 ,  C22C38/16 ,  C22C38/14 ,  C22C38/12 ,  C22C38/08 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  C23F17/00 ,  B32B15/01 ,  C23C2/06 ,  C22C38/60 ,  C21D8/04 ,  C22C38/18 ,  C23C2/28 ,  C23C2/40 ,  C21D1/18 ,  C21D1/25 ,  C22C18/04 ,  C25D3/22

Abstract: A high-strength cold rolled steel sheet having a specified chemical composition and a method for producing the same. The steel sheet having a microstructure including, in terms of volume fraction, 35% or less of ferrite, 1% or more and 10% or less of retained austenite, 2% or more and 12% or less of as-quenched martensite, and a total of 25% to 70% of bainite and tempered martensite. The microstructure has an average crystal grain diameter of the ferrite: 5.0 μm or less, an average crystal grain diameter of the retained austenite: 2.0 μm or less, an average crystal grain diameter of the as-quenched martensite: 3.0 μm or less, an average crystal grain diameter of the bainite and the tempered martensite phase: 4.0 μm or less, and an average intergrain distance of the as-quenched martensite of 1.0 μm or more.

公开(公告)号：US10570475B2

公开(公告)日：2020-02-25

申请号：US15327126

申请日：2015-08-05

Applicant: JFE STEEL CORPORATION

Inventor： Yoshiyasu Kawasaki ,  Hiroshi Matsuda ,  Yoshie Obata ,  Shinjiro Kaneko ,  Takeshi Yokota ,  Kazuhiro Seto

IPC: C21D9/46 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/32 ,  C22C38/14 ,  C22C38/60 ,  C21D8/02 ,  C23C2/28 ,  C23C2/40 ,  C23C2/06 ,  C22C38/12 ,  C22C38/28 ,  C22C38/38 ,  C22C18/04

Abstract: Disclosed is a high-strength steel sheet having a predetermined chemical composition, satisfying the condition that Mn content divided by B content equals 2100 or less, and a steel microstructure that contains, by area, 25-80% of ferrite and bainitic ferrite in total, 3-20% of martensite, and that contains, by volume, 10% or more of retained austenite, in which the retained austenite has a mean grain size of 2 μm or less, a mean Mn content in the retained austenite in mass % is at least 1.2 times the Mn content in the steel sheet in mass %, and an aggregate of retained austenite formed by seven or more identically-oriented retained austenite grains accounts for 60% or more by area of the entire retained austenite.