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：US20240360532A1

公开(公告)日：2024-10-31

申请号：US18681864

申请日：2022-06-21

Applicant: JFE STEEL CORPORATION

Inventor： Yuji TANAKA ,  Takeshi NISHIYAMA ,  Masanari TOMOZAWA ,  Kazuki ENDOH ,  Hidekazu MINAMI ,  Junya TOBATA ,  Yuki TOJI

IPC: C21D9/46 ,  C21D8/02 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12

CPC classification number: C21D9/46 ,  C21D8/0205 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0268 ,  C21D8/0273 ,  C21D8/0278 ,  C22C38/001 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12

Abstract: The steel sheet comprising a chemical composition containing C, Si, Mn, P, S, Al, N, Ti, Nb, and B, with the balance being Fe and inevitable impurities, and satisfying predetermined formula, in which the total area ratio of martensite and bainite is 95% or more, the average grain size of prior austenite grains is 10 μm or less, the B concentration at a prior austenite grain boundary is 0.10% or more in mass %, a C-concentrated region is provided along a martensitic grain boundary, and the C-concentrated region has a C concentration of 4.0 times or more than the C content in the steel, and the C-concentrated region has a concentration width of 3 nm or more and 100 nm or less in a direction perpendicular to the martensitic grain boundary and a length of 100 nm or more in a direction parallel to the martensitic grain boundary.

公开(公告)号：US20240425959A1

公开(公告)日：2024-12-26

申请号：US18576365

申请日：2022-05-17

Applicant: JFE STEEL CORPORATION

Inventor： Hidekazu MINAMI ,  Kazuki ENDOH ,  Yuki TOJI

IPC: C22C38/58 ,  C21D1/04 ,  C21D1/26 ,  C21D9/46 ,  C21D9/56 ,  C22C38/00 ,  C22C38/02 ,  C22C38/06 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C22C38/54 ,  C22C38/60 ,  C23C2/06

Abstract: Provided is a continuous annealing line capable of producing a steel sheet excellent in hydrogen embrittlement resistance. A continuous annealing line 100 includes: a payoff reel 10 to feed a cold-rolled steel sheet S; an annealing furnace 20 to continuously anneal the cold-rolled steel sheet S and including a heating zone 22, a soaking zone 24, and a cooling zone 26; a downstream line 30; a tension reel 50 configured to coil the cold-rolled steel sheet S; and a vibration application device 60 or 70 configured to apply vibration to the cold-rolled steel sheet S being passed from the cooling zone 26 to the tension reel 50 so that the cold-rolled steel sheet is caused to vibrate at a frequency of 100 Hz or more and 100,000 Hz or less and a maximum amplitude of 10 nm or more and 500 μm or less.

公开(公告)号：US20240376577A1

公开(公告)日：2024-11-14

申请号：US18682114

申请日：2022-06-21

Applicant: JFE STEEL CORPORATION

Inventor： Yuji TANAKA ,  Kazuki ENDOH ,  Hidekazu MINAMI ,  Junya TOBATA ,  Yuki TOJI

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

Abstract: The steel sheet comprising a chemical composition containing C, Si, Mn, P, S, Al, N, Ti, Nb, and B, with the balance being Fe and inevitable impurities, and satisfying predetermined formula (1), in which the total area ratio of martensite and bainite is 95% or more, the grain size of prior austenite grains is 10 μm or less, the B concentration at a prior austenite grain boundary is 0.10% or more in mass %, the C concentration at the prior austenite grain boundary is 1.5 times or more than the C content in the steel, the amount of precipitated Fe is 200 mass ppm or less, and for a defined in predetermined formula (2), a ratio of adislocation on dislocation to agrain boundary on the prior austenite grain boundary: adislocation/agrain boundary is 1.3 or more.

公开(公告)号：US20230256534A1

公开(公告)日：2023-08-17

申请号：US18005057

申请日：2021-05-26

Applicant: JFE STEEL CORPORATION

Inventor： Satoshi MAEDA ,  Kazuki ENDOH ,  Yuki TOJI ,  Nao KAWABE

IPC: B23K11/11 ,  B23K31/02 ,  B23K31/12

CPC classification number: B23K11/115 ,  B23K31/02 ,  B23K31/12

Abstract: Provided is a resistance spot welding method suitable for manufacturing a weld joint exhibiting excellent delayed fracture resistance. The resistance spot welding method includes sandwiching two or more overlapped steel sheets between a pair of welding electrodes, applying current to the steel sheets while pressing the steel sheets, forming a nugget on overlapping surfaces of the steel sheets to join the steel sheets, and after the joining, directly or indirectly irradiating the nugget with sound waves having a frequency of 10 Hz or more and 100000 Hz or less so that a sound pressure level on a surface of the steel sheet is 30 dB or more.

公开(公告)号：US20250163552A1

公开(公告)日：2025-05-22

申请号：US18730452

申请日：2022-11-28

Applicant: JFE STEEL CORPORATION

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

IPC: C22C38/04 ,  B22F10/28 ,  B33Y10/00 ,  B33Y70/00 ,  C22C38/00 ,  C22C38/02 ,  C22C38/06 ,  C22C38/08 ,  C22C38/10 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/38 ,  C22C38/60

Abstract: An additive manufacturing product that 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 additive manufacturing product 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, high-angle grain boundary length LHA divided by grain boundary length L with a misorientation angle of 20° or more and 50° or less, is 2.0 or more.

公开(公告)号：US20240368719A1

公开(公告)日：2024-11-07

申请号：US18565265

申请日：2022-03-28

Applicant: JFE STEEL CORPORATION

Inventor： Hidekazu MINAMI ,  Masayasu UENO ,  Yuki TOJI ,  Yuji TANAKA ,  Junya TOBATA ,  Kazuki ENDOH

IPC: C21D9/46 ,  C21D8/02 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06

Abstract: Provided is a high strength steel sheet with high stretch flangeability and high YR in the rolling direction as well as in the direction orthogonal to the rolling direction with TS of 1180 MPa or more. The high strength steel sheet has a prescribed chemical composition and steel microstructure. In particular, an average grain size of the hard phase is 5.3 μm or less, the volume fraction-carbon concentration ratio of retained austenite (γ) is 0.10 or more and 0.45 or less, and the integration degree of {112} orientation is 1.0 or more.

公开(公告)号：US20230357883A1

公开(公告)日：2023-11-09

申请号：US18004880

申请日：2021-05-07

Applicant: JFE STEEL CORPORATION

Inventor： Yuki TOJI ,  Kazuki ENDOH ,  Hidekazu MINAMI

IPC: C21D10/00 ,  C21D9/46 ,  C21D8/02 ,  C21D6/00 ,  C22C38/60 ,  C22C38/40 ,  C22C38/38 ,  C22C38/28 ,  C22C38/26 ,  C22C38/22 ,  C22C38/20 ,  C22C38/16 ,  C22C38/14 ,  C22C38/12 ,  C22C38/08 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00

CPC classification number: C21D10/00 ,  C21D9/46 ,  C21D8/0205 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0263 ,  C21D8/0278 ,  C21D6/001 ,  C21D6/002 ,  C21D6/004 ,  C21D6/005 ,  C21D6/008 ,  C22C38/60 ,  C22C38/40 ,  C22C38/38 ,  C22C38/28 ,  C22C38/26 ,  C22C38/22 ,  C22C38/20 ,  C22C38/16 ,  C22C38/14 ,  C22C38/12 ,  C22C38/08 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/008 ,  C22C38/005 ,  C22C38/002 ,  C22C38/001 ,  C23C2/40

Abstract: Provided are a steel sheet dehydrogenation apparatus, a steel sheet production system, and a steel sheet production method capable of producing a steel sheet excellent in hydrogen embrittlement resistance without changing the mechanical properties of the steel sheet. A dehydrogenation apparatus comprises: a housing configured to house a steel sheet coil obtained by coiling a steel strip; and a sound wave irradiator configured to irradiate the steel sheet coil housed in the housing with sound waves to obtain a product coil.

公开(公告)号：US20230265539A1

公开(公告)日：2023-08-24

申请号：US18005186

申请日：2021-05-11

Applicant: JFE STEEL CORPORATION

Inventor： Hidekazu MINAMI ,  Kazuki ENDOH ,  Yuki TOJI

IPC: C21D9/56 ,  C21D9/46 ,  C21D3/06 ,  C21D1/26 ,  C21D1/04 ,  C21D6/00 ,  C23C2/40 ,  C23C2/26 ,  C22C38/14 ,  C22C38/12 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00

CPC classification number: C21D9/562 ,  C21D9/561 ,  C21D9/46 ,  C21D3/06 ,  C21D1/26 ,  C21D1/04 ,  C21D6/008 ,  C21D6/005 ,  C23C2/40 ,  C23C2/26 ,  C22C38/14 ,  C22C38/12 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/002 ,  C22C38/001 ,  C21D2241/00 ,  C22C2202/04

Abstract: Provided is a continuous annealing line capable of producing a steel sheet excellent in hydrogen embrittlement resistance. A continuous annealing line 100 comprises: a payoff reel 10 configured to uncoil a cold-rolled coil C to feed a cold-rolled steel sheet S; an annealing furnace 20 configured to continuously anneal the cold-rolled steel sheet S and including a heating zone 22, a soaking zone 24, and a cooling zone 26 that are arranged from an upstream side in a sheet passing direction; a downstream line 30 configured to continuously pass the cold-rolled steel sheet S discharged from the annealing furnace 20 therethrough; a tension reel 50 configured to coil the cold-rolled steel sheet S; and a sound wave irradiator 60 configured to irradiate the cold-rolled steel sheet S being passed from the cooling zone 26 to the tension reel 50 with sound waves.

公开(公告)号：US20240352549A1

公开(公告)日：2024-10-24

申请号：US18574068

申请日：2022-05-17

Applicant: JFE STEEL CORPORATION

Inventor： Yuki TOJI ,  Kazuki ENDOH ,  Hidekazu MINAMI

IPC: C21D3/10 ,  C21D3/06 ,  C21D10/00 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/24 ,  C22C38/26 ,  C22C38/38 ,  C22C38/60

CPC classification number: C21D3/10 ,  C21D3/06 ,  C21D10/00 ,  C22C38/001 ,  C22C38/002 ,  C22C38/005 ,  C22C38/008 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/24 ,  C22C38/26 ,  C22C38/38 ,  C22C38/60

Abstract: Provided are a steel sheet dehydrogenation apparatus, a steel sheet production system, and a steel sheet production method capable of producing a steel sheet excellent in hydrogen embrittlement resistance without changing the mechanical properties of the steel sheet. A dehydrogenation apparatus comprises: a housing configured to house a steel sheet coil obtained by coiling a steel strip; and a vibration application device configured to apply vibration to the steel sheet coil housed in the housing so that the steel sheet coil is caused to vibrate at a frequency of 100 Hz to 100,000 Hz and a maximum amplitude of 10 nm to 500 μm.