公开(公告)号：US20210054488A1

公开(公告)日：2021-02-25

申请号：US17041223

申请日：2019-03-19

申请人： Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)

发明人： Haruka ARAKI ,  Sae HAMAMOTO ,  Tatsuya ASAI

IPC分类号： C22C38/54 ,  C22C38/42 ,  C22C38/50 ,  C22C38/32 ,  C22C38/28 ,  C22C38/26 ,  C22C38/24 ,  C22C38/22 ,  C22C38/20 ,  C22C38/06 ,  C22C38/02 ,  C22C38/04 ,  C22C38/00 ,  C21D9/48 ,  C21D8/04 ,  C21D1/673 ,  C21D6/00

摘要： A steel plate for hot stamping contains, in % by mass, C: 0.25% or more and 0.4% or less, Si: 1.05% or more and 1.4% or less, Mn: 0% or more and 1.4% or less, Cr: 0.6% or more and 3.0% or less, P: 0% or more and 0.03% or less, S: 0% or more and 0.02% or less, Al: 0.01% or more and 1% or less, N: 0% or more and 0.01% or less, B: 0.0005% or more and 0.005% or less, Ti: 0.005% or more and 0.1% or less, and iron and inevitable impurities as remainder. This steel plate for hot stamping exhibits excellent hardness stability in addition to a balance between strength and toughness as a relational expression of [C]2/9[Si]+7/9[Mn]+8/9[Cr]−7/4>0 is satisfied.

公开(公告)号：US20240240298A1

公开(公告)日：2024-07-18

申请号：US18559094

申请日：2022-05-16

申请人： Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)

发明人： Sae HAMAMOTO ,  Haruka ARAKI ,  Michitaka TSUNEZAWA

IPC分类号： C23C2/06 ,  C21D8/02 ,  C21D9/46 ,  C22C38/00 ,  C22C38/02 ,  C22C38/06 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C22C38/54 ,  C22C38/58 ,  C22C38/60 ,  C23C2/40

CPC分类号： C23C2/06 ,  C21D8/0226 ,  C21D8/0236 ,  C21D8/0247 ,  C21D9/46 ,  C22C38/001 ,  C22C38/002 ,  C22C38/005 ,  C22C38/02 ,  C22C38/06 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C22C38/54 ,  C22C38/58 ,  C22C38/60 ,  C23C2/40 ,  C21D2211/001 ,  C21D2211/002 ,  C21D2211/005 ,  C21D2211/008 ,  C21D2211/009

摘要： A high-strength hot-dip galvannealed steel sheet may include a plating layer on a surface of a base steel sheet. The base steel sheet may satisfy a predetermined chemical composition, in a metallographic structure of the base steel sheet, wherein a volume ratio of martensite (including tempered martensite and self-tempered martensite) is 82 vol % or more, a volume ratio of ferrite, pearlite and bainite is 13 vol % or less in total, and volume ratio of retained austenite is 5 vol % or less, in an image obtained by observing the metallographic structure of the base steel sheet with a scanning electron microscope, the number of laths at a total length of 300 μm, the number being measured by an intercept method is 200 or more, a yield strength is 970 MPa or more, and a tensile strength is 1,470 MPa or more.

公开(公告)号：US20210115542A1

公开(公告)日：2021-04-22

申请号：US17041290

申请日：2019-03-11

申请人： Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)

发明人： Michitaka TSUNEZAWA ,  Michiharu NAKAYA ,  Haruka ARAKI

IPC分类号： C22C38/38 ,  B32B15/01 ,  C21D9/46 ,  C21D8/02 ,  C21D6/00 ,  C22C38/32 ,  C22C38/28 ,  C22C38/24 ,  C22C38/22 ,  C22C38/06 ,  C22C38/02 ,  C22C38/00 ,  C23C2/06 ,  C23C2/28 ,  C23C2/40

摘要： A high-strength steel sheet satisfies a predetermined chemical composition in which a content of martensite is 93% by volume or more, contents of ferrite, pearlite, and bainite are 2% by volume or less in total, and a content of retained austenite is 7% by volume or less, based on an entire metal structure, a number of laths in martensite measured by a cutting method in a total length of 300 μm in an image of the metal structure observed under a scanning electron microscope is 240 or more, and a tensile strength of the high-strength steel sheet is 1470 MPa or more.