Hot-stamped member and steel sheet for hot stamping

Patent metadata

Field	Value
Publication number	US-12509754-B2
Application number	US-202017777574-A
Country	US
Kind code	B2
Filing date	Nov 25, 2020
Priority date	Nov 26, 2019
Publication date	Dec 30, 2025
Grant date	Dec 30, 2025

Abstract

There is provided a hot-stamped member or a steel sheet for hot stamping having a chemical composition including, in mass %, C: 0.25% or more and 0.55% or less, Si: 0.001% or more and 2.0% or less, Mn: 0.3% or more and 3.0% or less, P: 0.02% or less, S: 0.003% or less, Al: 0.005% or more and 1.0% or less, Cr: 0% or more and 1.0% or less, Mo: 0% or more and 1.0% or less, N: 0.02% or less, Ca: 0% or more and 0.0010% or less, B: 0.0005% or more and 0.01% or less, one or two or more selected from the group consisting of Ti: 0.005% or more and 0.5% or less, Nb: 0.005% or more and 0.5% or less, V: 0.005% or more and 0.5% or less, and Zr: 0.005% or more and 0.5% or less, and Ni+Cu+Sn: 0% or more and 2% or less, and a remainder consisting of Fe and impurities.

First claim

The invention claimed is:

1 . A hot-stamped member having a chemical composition including, in mass %,
C: 0.25% or more and 0.55% or less, Si: 0.001% or more and 2.0% or less, Mn: 0.3% or more and 3.0% or less, P: 0.02% or less, S: 0.003% or less, Al: 0.005% or more and 1.0% or less, Cr: 0% or more and 1.0% or less, Mo: 0% or more and 1.0% or less, N: 0.02% or less, Ca: 0% or more and 0.0010% or less, B: 0.0005% or more and 0.01% or less, at least one selected from the group of Ti: 0.005% or more and 0.5% or less, Nb: 0.005% or more and 0.5% or less, V: 0.005% or more and 0.5% or less, and Zr: 0.005% or more and 0.5% or less, Ni+Cu+Sn: 0% or more and 2% or less, and a remainder comprising Fe and impurities, wherein a tensile strength of the hot-stamped member left in the air at a room temperature of 20 to 30° C. for 48 hours or longer exceeds 1600 MPa, and wherein a major axis of an inclusion containing CaO—Al 2 O 3 contained in the hot-stamped member is 50 μm or less.

2 . The hot-stamped member according to claim 1 ,
wherein a maximum length of MnS present in a central part of a sheet thickness is 300 μm or less.

3 . The hot-stamped member according to claim 2 , including, in mass %,
Ni+Cu+Sn: 0.005% or more and 2% or less.

4 . The hot-stamped member according to claim 2 ,
wherein a plating layer is provided on a surface.

5 . The hot-stamped member according to claim 1 , including, in mass %,
Ni+Cu+Sn: 0.005% or more and 2% or less.

6 . The hot-stamped member according to claim 1 ,
wherein a plating layer is provided on a surface.

7 . A hot-stamped member having a chemical composition including, in mass %,
C: 0.25% or more and 0.55% or less, Si: 0.001% or more and 2.0% or less, Mn: 0.3% or more and 3.0% or less, P: 0.02% or less, S: 0.003% or less, Al: 0.005% or more and 1.0% or less, Cr: 0% or more and 1.0% or less, Mo: 0% or more and 1.0% or less, N: 0.02% or less, Ca: 0% or more and 0.0010% or less, B: 0.0005% or more and 0.01% or less, at least one selected from the group of Ti: 0.005% or more and 0.5% or less, Nb: 0.005% or more and 0.5% or less, V: 0.005% or more and 0.5% or less, and Zr: 0.005% or more and 0.5% or less, Ni+Cu+Sn: 0% or more and 2% or less, and a remainder comprising Fe and impurities, wherein a tensile strength of the hot-stamped member left in the air at a room temperature of 20 to 30° C. for 48 hours or longer exceeds 1600 MPa, wherein, when a uniform elongation is El 1 (%) and a total elongation measured using a tensile test piece of the hot-stamped member charged with hydrogen so that an amount of diffusible hydrogen is 0.5±0.1 wt. ppm is El 2 (%), (El 2 /El 1 )×100≥100(%) is satisfied.

8 . The hot-stamped member according to claim 7 ,
wherein a maximum length of MnS present in a central part of a sheet thickness is 300 μm or less.

9 . The hot-stamped member according to claim 7 , including, in mass %,
Ni+Cu+Sn: 0.005% or more and 2% or less.

10 . The hot-stamped member according to claim 7 ,
wherein a plating layer is provided on a surface.

11 . A steel sheet for hot stamping having a chemical composition including, in mass %,
C: 0.25% or more and 0.55% or less, Si: 0.001% or more and 2.0% or less, Mn: 0.3% or more and 3.0% or less, P: 0.02% or less, S: 0.003% or less, Al: 0.005% or more and 1.0% or less, Cr: 0% or more and 1.0% or less, Mo: 0% or more and 1.0% or less, N: 0.02% or less, Ca: 0% or more and 0.0010% or less, B: 0.0005% or more and 0.01% or less, at least one selected from the group of Ti: 0.005% or more and 0.5% or less, Nb: 0.005% or more and 0.5% or less, V: 0.005% or more and 0.5% or less, and Zr: 0.005% or more and 0.5% or less, Ni+Cu+Sn: 0% or more and 2% or less, and a remainder comprising Fe and impurities, wherein a tensile strength measured using a tensile test piece obtained by heating the steel sheet for hot stamping at 950° C. for 1 minute and then cooling to 200° C. or lower at an average cooling rate of 30 to 100° C./s, the steel sheet for hot stamping being left in the air at a room temperature of 20 to 30° C. for 48 hours or longer, exceeds 1600 MPa, and wherein a major axis of an inclusion containing CaO—Al 2 O 3 contained in the steel sheet for hot stamping is 50 μm or less.

12 . The steel sheet for hot stamping according to claim 11 ,
wherein a maximum length of MnS present in a central part of a sheet thickness is 300 μm or less.

13 . The steel sheet for hot stamping according to claim 12 , including, in mass %,
Ni+Cu+Sn: 0.005% or more and 2% or less.

14 . The steel sheet for hot stamping according to claim 12 ,
wherein a plating layer is provided on a surface.

15 . The steel sheet for hot stamping according to claim 11 , including, in mass %,
Ni+Cu+Sn: 0.005% or more and 2% or less.

16 . The steel sheet for hot stamping according to claim 11 ,
wherein a plating layer is provided on a surface.

17 . A steel sheet for hot stamping having a chemical composition including, in mass %,
C: 0.25% or more and 0.55% or less, Si: 0.001% or more and 2.0% or less, Mn: 0.3% or more and 3.0% or less, P: 0.02% or less, S: 0.003% or less, Al: 0.005% or more and 1.0% or less, Cr: 0% or more and 1.0% or less, Mo: 0% or more and 1.0% or less, N: 0.02% or less, Ca: 0% or more and 0.0010% or less, B: 0.0005% or more and 0.01% or less, at least one selected from the group of Ti: 0.005% or more and 0.5% or less, Nb: 0.005% or more and 0.5% or less, V: 0.005% or more and 0.5% or less, and Zr: 0.005% or more and 0.5% or less, Ni+Cu+Sn: 0% or more and 2% or less, and a remainder comprising Fe and impurities, wherein a tensile strength measured using a tensile test piece obtained by heating the steel sheet for hot stamping at 950° C. for 1 minute and then cooling to 200° C. or lower at an average cooling rate of 30 to 100° C./s, the steel sheet for hot stamping being left in the air at a room temperature of 20 to 30° C. for 48 hours or longer, exceeds 1600 MPa, and wherein, when a uniform elongation is El 3 (%) and a total elongation measured using the tensile test piece charged with hydrogen so that an amount of diffusible hydrogen is 0.5±0.1 wt. ppm is El 4 (%), (El 4 /El 3 )×100≥100(%) is satisfied.

18 . The steel sheet for hot stamping according to claim 17 ,
wherein a maximum length of MnS present in a central part of a sheet thickness is 300 μm or less.

19 . The steel sheet for hot stamping according to claim 17 , including, in mass %,
Ni+Cu+Sn: 0.005% or more and 2% or less.

20 . The steel sheet for hot stamping according to claim 17 ,
wherein a plating layer is provided on a surface.

Assignees

• Nippon Steel Corp

Inventors

• Kusumi Kazuhisa
• Fuchigami Katsuhiro
• Aramaki Takashi
• Irikawa Hideaki
• Eguchi Haruhiko
• Honda Takahisa
• Morohoshi Takashi

Classifications

• C21D8/00

  Modifying the physical properties of ferrous metals or ferrous alloys by deformation combined with, or followed by, heat treatment (hardening articles or materials formed by forging or rolling with no further heating beyond that required for the formation C21D1/02) · CPC title

• C22C38/54

  with boron · CPC title

• C22C38/50

  with titanium or zirconium · CPC title

• C22C38/48

  with niobium or tantalum · CPC title

• C22C38/46

  with vanadium · CPC title