公开(公告)号：US20170121786A1

公开(公告)日：2017-05-04

申请号：US15129449

申请日：2015-03-26

Applicant: JFE STEEL CORPORATION

Inventor： Yuka MIYAMOTO ,  Takashi KOBAYASHI ,  Kaneharu OKUDA

IPC: C21D9/46 ,  C22C38/60 ,  C22C38/32 ,  C22C38/18 ,  C22C38/00 ,  C22C38/08 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C21D8/02 ,  C22C38/12

CPC classification number: C21D9/46 ,  C21D8/0226 ,  C21D8/0263 ,  C21D2211/003 ,  C21D2211/005 ,  C21D2211/009 ,  C22C38/00 ,  C22C38/001 ,  C22C38/002 ,  C22C38/008 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/18 ,  C22C38/32 ,  C22C38/60

Abstract: A high-carbon hot-rolled steel sheet having a chemical composition containing, by mass %, C: more than 0.40% and 0.63% or less, Si: 0.10% or less, Mn: 0.50% or less, P: 0.03% or less, S: 0.010% or less, sol.Al: 0.10% or less, N: 0.0050% or less, B: 0.0005% or more and 0.0050% or less, and at least one of Sb, Sn, Bi, Ge, Te, and Se in an amount of 0.002% or more and 0.030% or less in total. The steel sheet has a microstructure including ferrite and cementite, in which the density of cementite in ferrite grains is 0.13 pieces/μm2 or less. Additionally, the steel sheet has a hardness of 81 or less in terms of HRB and a total elongation of 33% or more.

公开(公告)号：US20170211163A1

公开(公告)日：2017-07-27

申请号：US15326811

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 ,  C21D6/00 ,  C22C38/60 ,  C22C38/38 ,  C22C38/16 ,  C23F17/00 ,  C22C38/12 ,  C22C38/06 ,  C22C38/00 ,  C22C38/04 ,  C22C38/02 ,  C23C2/06 ,  C21D8/02 ,  C22C38/14

CPC classification number: C21D9/46 ,  C21D6/005 ,  C21D6/008 ,  C21D8/0205 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0263 ,  C21D8/0278 ,  C21D2211/001 ,  C21D2211/005 ,  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 ,  C23F17/00

Abstract: Disclosed is a high-strength steel sheet having a tensile strength (TS) of 780 MPa or more and excellent in ductility, fatigue properties, balance between high strength and ductility, 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, and 5-20% 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 the retained austenite has a mean free path of 1.2 μm or less.

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：US20170121787A1

公开(公告)日：2017-05-04

申请号：US15129520

申请日：2015-03-26

Applicant: JFE STEEL CORPORATION

Inventor： Yuka MIYAMOTO ,  Takashi KOBAYASHI ,  Kaneharu OKUDA

IPC: C21D9/46 ,  C22C38/60 ,  C22C38/32 ,  C22C38/18 ,  C22C38/00 ,  C22C38/08 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C21D8/02 ,  C22C38/12

CPC classification number: C21D9/46 ,  C21D8/0226 ,  C21D8/0263 ,  C21D2211/003 ,  C21D2211/005 ,  C21D2211/009 ,  C22C38/00 ,  C22C38/001 ,  C22C38/002 ,  C22C38/008 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/18 ,  C22C38/32 ,  C22C38/60

Abstract: A high-carbon hot-rolled steel sheet having a chemical composition containing, by mass %, C: 0.20% or more and 0.40% or less, Si: 0.10% or less, Mn: 0.50% or less, P: 0.03% or less, S: 0.010% or less, sol.A1: 0.10% or less, N: 0.0050% or less, B: 0.0005% or more and 0.0050% or less, and at least one of Sb, Sn, Bi, Ge, Te, and Se in an amount of 0.002% or more and 0.030% or less in total. The steel sheet has a microstructure including ferrite and cementite, in which the density of cementite in the ferrite grains is 0.08 pieces/m2 or less. Additionally, the steel sheet has a hardness of 73 or less in terms of HRB and a total elongation of 39% or more.

公开(公告)号：US20160145709A1

公开(公告)日：2016-05-26

申请号：US14903842

申请日：2014-07-08

Applicant: JFE STEEL CORPORATION

Inventor： Yuka MIYAMOTO ,  Takashi KOBAYASHI ,  Chikara KAMI ,  Hayato SAITO ,  Kaneharu OKUDA

IPC: C21D9/46 ,  C22C38/06 ,  C22C38/04 ,  C21D1/26 ,  C22C38/00 ,  C21D8/02 ,  C21D6/00 ,  C22C38/60 ,  C22C38/02

CPC classification number: C21D9/46 ,  C21D1/26 ,  C21D1/32 ,  C21D1/74 ,  C21D6/005 ,  C21D6/008 ,  C21D8/0205 ,  C21D8/0226 ,  C21D8/0247 ,  C21D8/0263 ,  C21D2211/003 ,  C21D2211/005 ,  C22C38/00 ,  C22C38/001 ,  C22C38/002 ,  C22C38/008 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/60

Abstract: There is provided is a high-carbon hot-rolled steel sheet and method for producing the same. The steel sheet has excellent hardenability consistently, even when annealed in a nitrogen atmosphere, and excellent formability. The steel sheet has a hardness in the range of 83 HRB or less and a total elongation of 30% or more before being subjected to a quenching treatment.

Abstract translation: 提供一种高碳热轧钢板及其制造方法。 即使在氮气氛中退火，钢板也具有优异的淬透性，成型性优异。 在进行淬火处理之前，钢板的硬度为83HRC以下，总伸长率为30％以上。