公开(公告)号：US20160289784A1

公开(公告)日：2016-10-06

申请号：US15038223

申请日：2014-11-13

Applicant: JFE STEEL CORPORATION

Inventor： Yusuke FUSHIWAKI ,  Yoshiyasu KAWASAKI

IPC: C21D1/74 ,  C25F1/06 ,  C22C38/18 ,  C22C38/16 ,  C22C38/00 ,  C22C38/12 ,  C22C38/08 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C21D9/56 ,  C22C38/14

CPC classification number: C21D1/74 ,  C21D1/76 ,  C21D8/0447 ,  C21D9/46 ,  C21D9/56 ,  C21D2211/008 ,  C22C38/00 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/18 ,  C22C38/60 ,  C25F1/06

Abstract: A high-strength steel sheet and a method for manufacturing a high-strength steel sheet having excellent phosphatability and excellent corrosion resistance after electrodeposition coating has been performed, even in the case where the contents of Si and Mn are high. The method may comprise annealing a steal sheet by using a continuous annealing method, performing a heating process, controlling the maximum end-point temperature of a steel sheet in the annealing furnace, controlling the traveling time of the steel sheet, and controlling the dew point of the atmosphere.

Abstract translation: 即使在Si和Mn的含量高的情况下，也进行了高强度钢板和电沉积涂膜后具有优异的磷酸化性和优异的耐腐蚀性的高强度钢板的制造方法。 该方法可以包括通过使用连续退火法，进行加热处理，控制退火炉中的钢板的最大终点温度，控制钢板的行进时间，以及控制露点 的气氛。

公开(公告)号：US20250108434A1

公开(公告)日：2025-04-03

申请号：US18729889

申请日：2022-11-28

Applicant: JFE STEEL CORPORATION

Inventor： Kazuki ENDOH ,  Yoshiyasu KAWASAKI ,  Masaki TADA ,  Takuya TAKASHITA ,  Jun HORIUCHI ,  Hiroyuki MASUOKA

IPC: B22F1/12 ,  B22F10/28 ,  B33Y10/00 ,  B33Y70/10 ,  B33Y80/00

Abstract: An additive manufacturing product including a steel matrix and ceramic particles dispersed in the steel matrix. The steel matrix has a chemical composition containing, in mass %, C: 0.030% or more and 0.800% or less, Si: 0.01% or more and 2.50% or less, Mn: 0.10% or more and 8.00% or less, P: 0.100% or less, S: 0.0200% or less, Al: 0.100% or less, N: 0.1000% or less, and O: 0.5000% or less, with the balance being Fe and inevitable impurity. The steel matrix has a steel microstructure where area fraction of pores is 0.50% or less, area fraction of martensite in a region excluding pores is 90% or more, average aspect ratio of prior austenite grains is 1.5 or more, and LHA/L is 2.0 or more. Melting point of the ceramic particles is 2000° C. or more.

公开(公告)号：US20240150876A1

公开(公告)日：2024-05-09

申请号：US18549921

申请日：2022-02-28

Applicant: JFE STEEL CORPORATION

Inventor： Yoshiyasu KAWASAKI ,  Yuki TOJI ,  Tatsuya NAKAGAITO ,  Shinya YAMAGUCHI ,  Masayasu UENO ,  Katsutoshi TAKASHIMA ,  Tomohiro ONO

IPC: C22C38/04 ,  C21D3/06 ,  C21D6/00 ,  C21D8/02 ,  C21D9/46 ,  C22C38/02 ,  C22C38/06 ,  C23C2/06 ,  C23C2/28

CPC classification number: C22C38/04 ,  C21D3/06 ,  C21D6/005 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0273 ,  C21D9/46 ,  C22C38/02 ,  C22C38/06 ,  C23C2/06 ,  C23C2/28 ,  C21D2211/005

Abstract: A clad steel plate having tensile strength (TS) of 780 MPa or more, excellent bendability, collision resistance, and LME resistance. The clad steel plate having a base metal and a cladding metal on front and back surfaces of the base metal, and the chemical composition and microstructure of the base metal and the cladding metal being appropriately controlled so that the average Vickers hardness (HVL) of the cladding metal is 260 or less, the average Vickers hardness (HVL) of the cladding metal divided by the average Vickers hardness (HVB) of the base metal is 0.80 or less, the boundary roughness between the base metal and the cladding metal is 50 μm or less at the maximum height Ry, and the number of voids at the boundary between the base metal and the cladding metal is controlled to 20 or fewer per 10 mm length of the boundary.

公开(公告)号：US20230160032A1

公开(公告)日：2023-05-25

申请号：US17915696

申请日：2021-03-25

Applicant: JFE STEEL CORPORATION

Inventor： Lingling YANG ,  Yoshiyasu KAWASAKI ,  Hidekazu MINAMI ,  Tatsuya NAKAGAITO ,  Shotaro TERASHIMA ,  Shunsuke YAMAMOTO ,  Katsuya HOSHINO ,  Yuki TAKEDA

IPC: C21D9/46 ,  C23C2/40 ,  C23C2/06 ,  C21D8/02 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  B21C47/02

CPC classification number: C21D9/46 ,  C23C2/40 ,  C23C2/06 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0273 ,  C22C38/001 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  B21C47/02 ,  C21D2211/002 ,  C21D2211/005 ,  C21D2211/008 ,  C21D2211/001

Abstract: A steel sheet having a tensile strength (TS) of 780 MPa or more and less than 1180 MPa, high LME resistance, and good weld fatigue properties. The steel sheet has a specific chemical composition and a specific steel microstructure. Crystal grains containing an oxide of Si and/or Mn in a region within 4.9 μm in a thickness direction from a surface of the steel sheet have an average grain size in the range of 3 to 10 μm, the lowest Si concentration LSi and the lowest Mn concentration LMn in the region within 4.9 μm in the thickness direction from the surface of the steel sheet and a Si concentration TSi and a Mn concentration TMn at a quarter thickness position of the steel sheet satisfy a specified formula.

公开(公告)号：US20230151451A1

公开(公告)日：2023-05-18

申请号：US17915020

申请日：2021-03-25

Applicant: JFE STEEL CORPORATION

Inventor： Yoshiyasu KAWASAKI ,  Lingling YANG ,  Shotaro TERASHIMA ,  Tatsuya NAKAGAITO ,  Shunsuke YAMAMOTO ,  Katsuya HOSHINO ,  Yuki TAKEDA

IPC: C21D9/46 ,  C21D8/02 ,  C21D6/00 ,  C22C38/38 ,  C22C38/60 ,  C22C38/16 ,  C22C38/14 ,  C22C38/12 ,  C22C38/10 ,  C22C38/08 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  B32B15/01

CPC classification number: C21D9/46 ,  C21D8/0205 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0263 ,  C21D6/001 ,  C21D6/002 ,  C21D6/005 ,  C21D6/007 ,  C21D6/008 ,  C22C38/38 ,  C22C38/60 ,  C22C38/16 ,  C22C38/14 ,  C22C38/12 ,  C22C38/10 ,  C22C38/08 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/008 ,  C22C38/005 ,  C22C38/002 ,  C22C38/001 ,  B32B15/013 ,  C21D2211/001 ,  C21D2211/005

Abstract: A steel sheet with a tensile strength (TS) of 1180 MPa or more, a member, and a method for producing them. In a region of the steel sheet within 4.9 μm in the thickness direction, a region with a Si concentration not more than one-third of the Si concentration in the chemical composition of the steel sheet and with a Mn concentration not more than one-third of the Mn concentration in the chemical composition of the steel sheet has a thickness of 1.0 μm or more. The lowest Si concentration LSi and the lowest Mn concentration LMn in the region within 4.9 μm in the thickness direction from the surface of the steel sheet and a Si concentration TSi and a Mn concentration TMn at a quarter thickness position of the steel sheet satisfy the following formula (1):


LSi+LMn≤(TSi+TMn)/4  (1).

公开(公告)号：US20210010101A1

公开(公告)日：2021-01-14

申请号：US17042291

申请日：2019-03-20

Applicant: JFE STEEL CORPORATION

Inventor： Kazuki ENDO ,  Yoshiyasu KAWASAKI ,  Yuki TOJI ,  Yoshimasa FUNAKAWA ,  Mai AOYAMA

IPC: C21D9/46 ,  C22C38/38 ,  C22C38/28 ,  C22C38/16 ,  C22C38/12 ,  C22C38/08 ,  C22C38/06 ,  C22C38/02 ,  C22C38/00 ,  C21D8/02 ,  C21D6/00 ,  C23C2/02 ,  C23C2/06 ,  C23C2/28 ,  C23C2/40

Abstract: A high-strength steel sheet includes a steel structure with: ferrite being 35% to 80% and tempered martensite being greater than 5% and 20% or less in terms of area fraction; retained austenite being 8% or more in terms of volume fraction; an average grain size of: the ferrite being 6 μm or less; and the retained austenite being 3 μm or less; a value obtained by dividing an area fraction of blocky austenite by a sum of area fractions of lath-like austenite and the blocky austenite being 0.6 or more; a value obtained by dividing, by mass %, an average Mn content in the retained austenite by an average Mn content in the ferrite being 1.5 or more; and a value obtained by dividing, by mass %, an average C content in the retained austenite by an average C content in the ferrite being 3.0 or more.

公开(公告)号：US20190284656A1

公开(公告)日：2019-09-19

申请号：US16349422

申请日：2017-11-15

Applicant: JFE STEEL CORPORATION

Inventor： Yoshiyasu KAWASAKI ,  Takako YAMASHITA ,  Masayasu UENO ,  Yuki TOJI ,  Takashi KOBAYASHI ,  Yoshimasa FUNAKAWA

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

Abstract: To provide a high-strength steel sheet with excellent ductility and hole expansion formability, a yield ratio of less than 68%, and a tensile strength of 980 MPa or more, by having a predetermined chemical composition and a microstructure where ferrite is 15% or more and 55% or less and martensite is 15% or more and 30% or less in area ratio, retained austenite is 12% or more in volume fraction, the average grain size of ferrite, martensite and retained austenite is 4.0 μm or less, 2.0 μm or less and 2.0 μm or less respectively, the average aspect ratio of crystal grain of ferrite, martensite and retained austenite is each more than 2.0 and 15.0 or less, and the value obtained by dividing the Mn content (mass %) in retained austenite by the Mn content (mass %) in ferrite is 2.0 or more.

公开(公告)号：US20190271051A1

公开(公告)日：2019-09-05

申请号：US16349443

申请日：2017-11-15

Applicant: JFE STEEL CORPORATION

Inventor： Yoshiyasu KAWASAKI ,  Takako YAMASHITA ,  Masayasu UENO ,  Yuki TOJI ,  Takashi KOBAYASHI ,  Yoshimasa FUNAKAWA

IPC: C21D8/02 ,  C23C2/12 ,  C23C2/40 ,  C23C2/02 ,  C22C38/00 ,  C22C38/06 ,  C22C38/02 ,  C22C38/14 ,  C22C38/60 ,  C22C38/38 ,  C22C38/12 ,  C22C38/16 ,  C22C38/08 ,  C21D9/46

Abstract: To provide a high-strength steel sheet with excellent ductility and hole expansion formability, a yield ratio of less than 68%, and a tensile strength of 590 MPa or more, by having a predetermined chemical composition and a microstructure where ferrite is 35% or more and 80% or less and martensite is 5% or more and 25% or less in area ratio, retained austenite is 8% or more in volume fraction, the average grain size of ferrite, martensite and retained austenite is 6.0 μm or less, 3.0 μm or less and 3.0 μm or less respectively, the average aspect ratio of crystal grain of ferrite, martensite and retained austenite is each more than 2.0 and 15.0 or less, and the value obtained by dividing the Mn content (mass %) in retained austenite by the Mn content (mass %) in ferrite is 2.0 or more.

公开(公告)号：US20170218472A1

公开(公告)日：2017-08-03

申请号：US15326116

申请日：2015-08-05

Applicant: JFE STEEL CORPORATION

Inventor： Yoshiyasu KAWASAKI ,  Hiroshi MATSUDA ,  Kazunori TAHARA ,  Takeshi YOKOTA ,  Kaneharu OKUDA ,  Kazuhiro SETO

IPC: C21D9/46 ,  C23C2/28 ,  C23C2/40 ,  C22C38/60 ,  C22C38/38 ,  C22C38/16 ,  C22C38/14 ,  C22C38/12 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  C21D8/02 ,  C21D1/60 ,  C23G1/00 ,  B32B15/01 ,  C23C2/06

CPC classification number: C21D9/46 ,  B32B15/013 ,  C21D1/60 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0263 ,  C21D8/0278 ,  C21D2211/001 ,  C21D2211/002 ,  C21D2211/005 ,  C21D2211/008 ,  C22C38/00 ,  C22C38/001 ,  C22C38/002 ,  C22C38/005 ,  C22C38/008 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/38 ,  C22C38/60 ,  C23C2/06 ,  C23C2/28 ,  C23C2/40 ,  C23G1/00

Abstract: Disclosed is a high-strength steel sheet having a tensile strength (TS) of 780 MPa or more and excellent in ductility, fatigue properties, stretch flangeability, surface characteristics, and sheet passage ability that can be obtained by providing a predetermined chemical composition and a steel microstructure that contains, by area, 20-50% of ferrite, 5-25% of bainitic ferrite, 1-10% of martensite, and 5-15% of tempered 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 %, the retained austenite has a mean free path of 1.2 μm or less, and the tempered martensite has a mean free path of 1.2 μm or less.

公开(公告)号：US20170204490A1

公开(公告)日：2017-07-20

申请号：US15326540

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 ,  C21D6/00 ,  C22C38/60 ,  C22C38/38 ,  C23F17/00 ,  C22C38/14 ,  C22C38/12 ,  C22C38/06 ,  C22C38/00 ,  C23C2/06 ,  C21D8/02 ,  C22C38/16

CPC classification number: C21D9/46 ,  C21D6/005 ,  C21D6/008 ,  C21D8/0205 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0263 ,  C21D8/0273 ,  C21D8/0278 ,  C21D2211/001 ,  C21D2211/002 ,  C21D2211/005 ,  C21D2211/008 ,  C22C18/04 ,  C22C38/00 ,  C22C38/001 ,  C22C38/002 ,  C22C38/005 ,  C22C38/008 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/38 ,  C22C38/60 ,  C23C2/02 ,  C23C2/06 ,  C23F17/00

Abstract: Disclosed is a high-strength steel sheet having a predetermined chemical composition and a steel microstructure that contains, by area, 25-80% of ferrite and bainitic ferrite in total, and 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 %, an area ratio of retained austenite having a mean C content in mass % at least 2.1 times the C content in the steel sheet in mass % is 60% or more of an area ratio of the entire retained austenite.