公开(公告)号：US20220267871A1

公开(公告)日：2022-08-25

申请号：US17663022

申请日：2022-05-12

Applicant: JFE STEEL CORPORATION

Inventor： Masanori TAKENAKA ,  Minoru TAKASHIMA ,  Yukihiro MATSUBARA

IPC: C21D8/12 ,  C22C38/60 ,  C22C38/00 ,  C22C38/04 ,  C22C38/06 ,  H01F1/16 ,  C22C38/34 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50

Abstract: Provided is a method of producing a hot-rolled steel sheet for a grain-oriented electrical steel sheet. The method comprising: preparing a steel slab having a chemical composition containing, by mass %, C: 0.002% or more and 0.080% or less, Si: 2.00% or more and 8.00% or less, Mn: 0.02% or more and 0.50% or less, acid-soluble Al: 0.003% or more and less than 0.010%, and at least one of S or Se: 0.001% or more and 0.010% or less in total, with N limited to less than 0.006%, and the balance being Fe and inevitable impurities; heating the steel slab to 1300° C. or lower; and subjecting the steel slab to hot rolling, wherein a friction coefficient in final pass of the hot rolling is 0.35 or less.

公开(公告)号：US20190271054A1

公开(公告)日：2019-09-05

申请号：US16078010

申请日：2017-03-09

Applicant: JFE STEEL CORPORATION

Inventor： Yuiko EHASHI ,  Masanori TAKENAKA ,  Yasuyuki HAYAKAWA ,  Minoru TAKASHIMA ,  Takeshi IMAMURA

IPC: C21D9/46 ,  C21D8/12 ,  C21D6/00 ,  C22C38/60 ,  C22C38/18 ,  C22C38/12 ,  C22C38/16 ,  C22C38/40 ,  C22C38/14 ,  C22C38/08 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00

Abstract: To provide a grain-oriented electrical steel sheet that has better magnetic property than conventional ones without requiring high-temperature slab heating, in the case of not performing intermediate annealing, the hot rolled steel sheet obtained by a predetermined step is subjected to hot band annealing, and, in a heating process in the hot band annealing, heating is performed at a heating rate of 10° C./s or less for 10 sec or more and 120 sec or less in a temperature range of 700° C. or more and 950° C. or less, and in the case of performing the intermediate annealing, in a heating process in final intermediate annealing, heating is performed at a heating rate of 10° C./s or less for 10 sec or more and 120 sec or less in a temperature range of 700° C. or more and 950° C. or less.

公开(公告)号：US20190161817A1

公开(公告)日：2019-05-30

申请号：US16320612

申请日：2017-07-25

Applicant: JFE STEEL CORPORATION

Inventor： Masanori TAKENAKA ,  Minoru TAKASHIMA ,  Yukihiro MATSUBARA

IPC: C21D8/12 ,  C22C38/60 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C22C38/34 ,  C22C38/00

Abstract: Provided is a technique to reduce the variations in magnetic properties in a coil. A hot-rolled steel sheet for a grain-oriented electrical steel sheet having a chemical composition containing, by mass %, C: 0.002% or more and 0.080% or less, Si: 2.00% or more and 8.00% or less, Mn: 0.02% or more and 0.50% or less, acid-soluble Al: 0.003% or more and less than 0.010%, and at least one of S or Se: 0.001% or more and 0.010% or less in total, with N limited to less than 0.006%, and the balance being Fe and inevitable impurities, where regions from an outermost surface layer and a bottommost surface layer to a depth of 1/4 sheet thickness have a recrystallization ratio of 90% or less.

公开(公告)号：US20190247902A1

公开(公告)日：2019-08-15

申请号：US16342015

申请日：2017-10-18

Applicant: JFE STEEL CORPORATION

Inventor： Yuiko EHASHI ,  Masanori TAKENAKA ,  Takeshi IMAMURA ,  Minoru TAKASHIMA

IPC: B21B45/08 ,  C22C38/60 ,  C22C38/40 ,  C22C38/34 ,  C22C38/16 ,  C22C38/14 ,  C22C38/12 ,  C22C38/06 ,  C22C38/04 ,  C22C38/00 ,  C21D9/46 ,  C21D8/12 ,  C21D8/00 ,  C21D6/00

CPC classification number: B21B45/08 ,  C21D6/004 ,  C21D6/005 ,  C21D6/008 ,  C21D8/005 ,  C21D8/12 ,  C21D8/1222 ,  C21D9/46 ,  C22C38/00 ,  C22C38/001 ,  C22C38/002 ,  C22C38/008 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/34 ,  C22C38/40 ,  C22C38/60

Abstract: With a hot-rolled steel sheet for electrical steel sheet production having a scale layer on the surface, where the surface of the steel sheet has a lightness L* as defined in JIS Z 8781-4: 2013 satisfying 30≤L*≤50, and chromaticities a* and b* as defined in JIS Z 8781-4: 2013 satisfying −1≤a*≤2 and −5≤b*≤3 respectively, and with one end portion in the longitudinal direction of a coil as a reference, a color difference ΔEab* as defined in JIS Z 8781-4: 2013 at the central portion and at the opposite end portion satisfies ΔEab*≤8, it is possible to obtain a grain-oriented electrical steel sheet where the variation of properties in a product coil is small.

公开(公告)号：US20190055619A1

公开(公告)日：2019-02-21

申请号：US16079669

申请日：2017-03-07

Applicant: JFE STEEL CORPORATION

Inventor： Takeshi IMAMURA ,  Minoru TAKASHIMA ,  Yuiko EHASHI ,  Yasuyuki HAYAKAWA

IPC: C21D9/46 ,  C21D8/02 ,  C21D8/12 ,  C21D6/00 ,  C22C38/60 ,  C22C38/04 ,  C22C38/02 ,  C22C38/06 ,  C22C38/00

Abstract: To provide a grain-oriented electrical steel sheet that has better magnetic property than conventional ones, in hot band annealing of the hot rolled steel sheet obtained by a predetermined step, an average heating rate from ordinary temperature to 400° C. is set to 50° C./s or more, and a time to reach 900° C. from 400° C. is set to 100 sec or less.