公开(公告)号：US20220403480A1

公开(公告)日：2022-12-22

申请号：US17821476

申请日：2022-08-23

Applicant: JFE STEEL CORPORATION

Inventor： Gentaro TAKEDA ,  Yoichi MAKIMIZU ,  Yoshikazu SUZUKI ,  Yoshimasa HIMEI ,  Hideyuki TAKAHASHI

IPC: C21D9/46 ,  C21D1/26 ,  C21D1/74 ,  C21D8/02 ,  C21D9/00 ,  C22C38/02 ,  C23C2/00 ,  C23C2/06 ,  C23C2/26 ,  C23C2/40

Abstract: A continuous hot-dip galvanizing apparatus has a vertical annealing furnace, one or more hearth rolls, a hot-dip galvanizing apparatus, an alloying line, and humidified gas supply ports. When the steel sheet having a Si content of 0.2 mass % or more is conveyed inside the annealing furnace, the humidified gas supply ports positioned in a latter part of the soaking zone supply the humidified gas to the soaking zone and the at least one dry gas supply port supplies the dry gas to the soaking zone. When the steel sheet having a Si content of less than 0.2 mass % is conveyed inside the annealing furnace, the plurality of the humidified gas supply ports do not supply the humidified gas to the soaking zone and the at least one dry gas supply port supplies the dry gas to the soaking zone.

公开(公告)号：US20200299799A1

公开(公告)日：2020-09-24

申请号：US16605305

申请日：2018-02-19

Applicant: JFE STEEL CORPORATION

Inventor： Gentaro TAKEDA ,  Yoichi MAKIMIZU ,  Yoshikazu SUZUKI ,  Yoshimasa HIMEI ,  Hideyuki TAKAHASHI

IPC: C21D9/46 ,  C21D9/00 ,  C21D1/26 ,  C21D1/74 ,  C21D8/02 ,  C23C2/00 ,  C23C2/06 ,  C23C2/26 ,  C23C2/40 ,  C22C38/02

Abstract: Provided is a method for producing a galvannealed steel sheet. When the steel sheet passing through the soaking zone is a type of steel containing 0.2 mass % or more of Si, both dry gas and humidified gas are supplied to the soaking zone, where the humidified gas is supplied only from the humidified gas supply port positioned in a latter part of the soaking zone among a plurality of humidified gas supply ports, where the latter part of the soaking zone is determined considering a sheet passing speed V and a target temperature T on the exit side of the soaking zone.

公开(公告)号：US20180237896A1

公开(公告)日：2018-08-23

申请号：US15753260

申请日：2016-08-05

Applicant: JFE STEEL CORPORATION

Inventor： Gentaro TAKEDA ,  Hideyuki TAKAHASHI ,  Yoichi MAKIMIZU ,  Yoshikazu SUZUKI ,  Yoshimasa HIMEI

IPC: C23C2/02 ,  C23C2/40 ,  C23C2/28 ,  C23C2/06 ,  C21D1/76 ,  C21D9/56 ,  C21D9/573

CPC classification number: C23C2/02 ,  C21D1/76 ,  C21D9/561 ,  C21D9/573 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C23C2/06 ,  C23C2/28 ,  C23C2/40

Abstract: A method includes: annealing a steel strip by conveying the steel strip through a heating zone, a soaking zone, and a cooling zone in this order inside an annealing furnace; and applying a hot-dip galvanized coating onto the steel strip discharged from the cooling zone. Reducing gas or non-oxidizing gas supplied into the soaking zone includes humidified gas and dry gas. While a width and a sheet passing speed of the steel strip passing through the soaking zone are constant, a variation of pressure in the annealing furnace is suppressed by adjusting a flow rate of the dry gas, and a variation range of an amount of moisture supplied into the soaking zone by the humidified gas is limited to 20% or less.

公开(公告)号：US20250034673A1

公开(公告)日：2025-01-30

申请号：US18715826

申请日：2022-07-28

Applicant: JFE Steel Corporation

Inventor： Hirokazu KOBAYASHI ,  Gentaro TAKEDA ,  Munesuke SUZUKI ,  Kazuki OKAMOTO ,  Hidenori SHIMADA

IPC: C21D9/573 ,  C21D1/18

Abstract: An apparatus for manufacturing a steel strip, includes: a first water tank part that stores cooling water for immersing and cooling a steel strip; a water cooling nozzle unit that is provided in the first water tank part and injects cooling water to a surface of the steel strip; a second water tank part connected to the first water tank part through a joining port; an opening and closing door that opens and closes the joining port; and a conveyance control part that conveys the water cooling nozzle unit such that the water cooling nozzle unit passes through the joining port and is positioned at either a cooling water injection position inside the first water tank part or a non-water cooling standby position inside the second water tank part.

公开(公告)号：US20240254612A1

公开(公告)日：2024-08-01

申请号：US18289266

申请日：2022-03-25

Applicant: JFE STEEL CORPORATION

Inventor： Maiko HIYAMA ,  Hideyuki TAKAHASHI ,  Gentaro TAKEDA

IPC: C23C2/00 ,  C23C2/20 ,  C23C2/40

CPC classification number: C23C2/50 ,  C23C2/004 ,  C23C2/20 ,  C23C2/40

Abstract: A steel-sheet non-plating defect prediction method in manufacturing equipment of a hot-dip galvanized steel sheet which equipment includes an annealing furnace, and a plating device arranged on a downstream side of the annealing furnace, the method includes: predicting steel-sheet non-plating defect information on an exit side of the manufacturing equipment by using a non-plating defect prediction model which is learned by machine learning, the non-plating defect prediction model for which an input data is data including one or two or more parameters selected from attribute information of a steel sheet charged into the manufacturing equipment, one or two or more operational parameters selected from operational parameters of the annealing furnace, and one or two or more operational parameters selected from operational parameters of the plating device, and an output data is non-plating defect information of the steel sheet on the exit side of the manufacturing equipment.

公开(公告)号：US20200377964A1

公开(公告)日：2020-12-03

申请号：US16955041

申请日：2018-11-20

Applicant: JFE STEEL CORPORATION

Inventor： Gentaro TAKEDA ,  Hideyuki TAKAHASHI ,  Tetsuya IWATA ,  Koji SAWAMURA

IPC: C21D9/46 ,  C21D9/56 ,  C23C2/06 ,  C23C2/40 ,  C21D1/26 ,  C22C38/02

Abstract: A method for producing a hot-dip galvanized steel sheet includes supplying humidified gas to the soaking zone 12 in a manner such that: in passes in which the steel sheet moves upward, the humidified gas is supplied from first humidified gas supply ports 40A to 40E provided at positions higher by 1.0 m or more and 5.0 m or less than the centers of lower hearth rolls 54 and overlapping the steel sheet in the passes when viewed from the side of the soaking zone; and in passes in which the steel sheet moves downward, the humidified gas is supplied from second humidified gas supply ports 42A to 42E provided at positions lower by 1.0 m or more and 5.0 m or less than the centers of the upper hearth rolls 52 and overlapping the steel sheet in the passes when viewed from the side of the soaking zone.

公开(公告)号：US20240229186A1

公开(公告)日：2024-07-11

申请号：US18558192

申请日：2022-02-08

Applicant: JFE STEEL CORPORATION

Inventor： Gentaro TAKEDA ,  Hideyuki TAKAHASHI ,  Yuki TAKEDA

IPC: C21D11/00 ,  C21D1/76 ,  C21D6/00 ,  C21D9/46 ,  C23C2/02 ,  C23C2/06 ,  C23C2/28

CPC classification number: C21D11/00 ,  C21D1/76 ,  C21D6/005 ,  C21D9/46 ,  C23C2/022 ,  C23C2/06 ,  C23C2/28

Abstract: Provided are a dew point control method for a continuous annealing furnace, a continuous annealing method for a steel sheet, a steel sheet manufacturing method, a continuous annealing furnace, a continuous hot-dip galvanizing line, and a galvannealing line by which a furnace dew point can be controlled in a short time. The dew point control method includes stopping or reducing supply of humidified gas into the furnace, and supplying dry gas along a furnace inner wall of the continuous annealing furnace in the continuous annealing furnace. According to the dew point control method, a temperature of the furnace inner wall of the continuous annealing furnace may be at least 30° C. higher than a furnace atmosphere temperature in the continuous annealing furnace.

公开(公告)号：US20170253943A1

公开(公告)日：2017-09-07

申请号：US15509353

申请日：2015-08-20

Applicant: JFE STEEL CORPORATION

Inventor： Yoichi MAKIMIZU ,  Yoshitsugu SUZUKI ,  Hideyuki TAKAHASHI ,  Gentaro TAKEDA ,  Koichiro FUJITA

IPC: C21D9/46 ,  C23C2/06 ,  C23C2/02 ,  C23C2/40 ,  C23F17/00 ,  C22C38/32 ,  C22C38/18 ,  C22C38/16 ,  C22C38/14 ,  C22C38/12 ,  C22C38/08 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  C21D8/02

CPC classification number: C21D9/46 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0273 ,  C21D8/0278 ,  C22C38/00 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/18 ,  C22C38/32 ,  C23C2/02 ,  C23C2/06 ,  C23C2/28 ,  C23C2/40 ,  C23F17/00

Abstract: A method for producing high-strength galvanized steel sheets having excellent coating adhesion, workability and appearance. The method comprises hot rolling a slab comprising, by mass %, C: 0.05 to 0.30%, Si: 0.1 to 2.0% and Mn: 1.0 to 4.0%, then coiling the steel sheet into a coil at a specific temperature TC, and pickling the steel sheet, cold rolling the hot-rolled steel sheet resulting from the hot rolling, annealing the cold-rolled steel sheet resulting from the cold rolling under specific conditions, and galvanizing the annealed sheet resulting from the annealing in a galvanizing bath containing 0.12 to 0.22 mass % Al.

公开(公告)号：US20230323501A1

公开(公告)日：2023-10-12

申请号：US18332752

申请日：2023-06-12

Applicant: JFE STEEL CORPORATION

Inventor： Gentaro TAKEDA ,  Hideyuki TAKAHASHI ,  Tetsuya IWATA ,  Koji SAWAMURA

IPC: C21D9/46 ,  C21D1/26 ,  C21D9/56 ,  C22C38/02 ,  C23C2/06 ,  C23C2/40

CPC classification number: C21D9/46 ,  C21D1/26 ,  C21D9/561 ,  C21D9/562 ,  C22C38/02 ,  C23C2/06 ,  C23C2/40

Abstract: Provided is a continuous hot-dip galvanizing apparatus comprising: a vertical annealing furnace having heating, soaking zone, and cooling zones therein; and a hot-dip galvanizing line downstream of the cooling zone. The heating, soaking, and cooling zones each have, in its upper portion, at least one upper hearth roll and, in its lower portion, at least one lower hearth roll. The soaking zone has a first and second humidified gas supply ports to supply a humidified gas having a dew point of 10° C. to 30° C. to the soaking zone. The first and second humidified gas supply ports are 1.0 m to 5.0 m lower than the center of the lower and upper hearth rolls, respectively, and overlap the steel sheet. The first humidified gas supply port is provided only for an ascending pass and the second humidified gas supply port is provided only for a descending pass.

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.