Hot-rolled steel sheet

Patent metadata

Field	Value
Publication number	US-11939650-B2
Application number	US-201917295298-A
Country	US
Kind code	B2
Filing date	Nov 20, 2019
Priority date	Nov 28, 2018
Publication date	Mar 26, 2024
Grant date	Mar 26, 2024

Abstract

A hot-rolled steel sheet includes, as chemical composition, C, Si, Mn, and sol.Al. In the hot-rolled steel sheet, an average of pole densities in crystal orientation group consisting of {110}<110> to {110}<001> in surface region is 0.5 to 3.0, a standard deviation of the pole densities in the crystal orientation group is 0.2 to 2.0, and the tensile strength is 780 to 1370 MPa.

First claim

What is claimed is:

1. A hot-rolled steel sheet comprising: a chemical composition consisting of, by mass %,
0.030 to 0.400% of C;
0.050 to 2.5% of Si;
1.00 to 4.00% of Mn;
0.001 to 2.0% of sol.Al;
0 to 0.20% of Ti;
0 to 0.20% of Nb;
0 to 0.010% of B;
0 to 1.0% of V;
0 to 1.0% of Cr;
0 to 1.0% of Mo;
0 to 1.0% of Cu;
0 to 1.0% of Co;
0 to 1.0% of W;
0 to 1.0% of Ni;
0 to 0.01% of Ca;
0 to 0.01% of Mg;
0 to 0.01% of REM;
0 to 0.01% of Zr;
limited to 0.020% or less of P;
limited to 0.020% or less of S;
limited to 0.010% or less of N; and
a balance of Fe and impurities, and
wherein, when a surface region is from a sheet surface to 1/10 of a sheet thickness, an average of pole densities in a crystal orientation group consisting of {110}<110>to {110}<001>in the surface region is 0.5 to 3.0, and a standard deviation of the pole densities in the crystal orientation group is 0.2 to 2.0, and
wherein a tensile strength is 780 to 1370 MPa.

2. The hot-rolled steel sheet according to claim 1 , wherein, when a central region is from 3/8 to 5/8 of the sheet thickness based on the sheet surface, a pole density in a crystal orientation of {334}<263>is 1.0 to 7.0.

3. The hot-rolled steel sheet according to claim 1 , the hot-rolled steel sheet comprising, as the chemical composition, by mass %, at least one of:
0.001 to 0.20% of Ti;
0.001 to 0.20% of Nb;
0.001 to 0.010% of B;
0.005 to 1.0% of V;
0.005 to 1.0% of Cr;
0.005 to 1.0% of Mo;
0.005 to 1.0% of Cu;
0.005 to 1.0% of Co;
0.005 to 1.0% of W;
0.005 to 1.0% of Ni;
0.0003 to 0.01% of Ca;
0.0003 to 0.01% of Mg;
0.0003 to 0.01% of REM; and
0.0003 to 0.01% of Zr.

4. The hot-rolled steel sheet according to claim 2 , the hot-rolled steel sheet comprising, as the chemical composition, by mass %, at least one of:
0.001 to 0.20% of Ti;
0.001 to 0.20% of Nb;
0.001 to 0.010% of B;
0.005 to 1.0% of V;
0.005 to 1.0% of Cr;
0.005 to 1.0% of Mo;
0.005 to 1.0% of Cu;
0.005 to 1.0% of Co;
0.005 to 1.0% of W;
0.005 to 1.0% of Ni;
0.0003 to 0.01% of Ca;
0.0003 to 0.01% of Mg;
0.0003 to 0.01% of REM; and
0.0003 to 0.01% of Zr.

5. A hot-rolled steel sheet comprising: as a chemical composition, by mass %,
0.030 to 0.400% of C;
0.050 to 2.5% of Si;
1.00 to 4.00% of Mn;
0.001 to 2.0% of sol.Al;
0 to 0.20% of Ti;
0 to 0.20% of Nb;
0 to 0.010% of B;
0 to 1.0% of V;
0 to 1.0% of Cr;
0 to 1.0% of Mo;
0 to 1.0% of Cu;
0 to 1.0% of Co;
0 to 1.0% of W;
0 to 1.0% of Ni;
0 to 0.01% of Ca;
0 to 0.01% of Mg;
0 to 0.01% of REM;
0 to 0.01% of Zr;
0.020% or less of P;
0.020% or less of S;
0.010% or less of N; and
a balance comprising Fe and impurities, and
wherein, when a surface region is from a sheet surface to 1/10 of a sheet thickness, an average of pole densities in a crystal orientation group comprising {110}<110>to {110}<001>in the surface region is 0.5 to 3.0, and a standard deviation of the pole densities in the crystal orientation group is 0.2 to 2.0, and
wherein a tensile strength is 780 to 1370 MPa.

Assignees

• Nippon Steel Corp

Inventors

• Yabu Shohei
• Hayashi Kunio
• Yamaguchi Yuji
• Mori Marina
• Inoue Naoki
• Abukawa Genki

Classifications

• C21D8/02

  during manufacturing of plates or strips (C21D8/12 takes precedence) · CPC title

• C22C38/06 Primary

  containing aluminium · CPC title

• C21D8/0205

  Chemistry & Metallurgy · mapped topic

• C21D8/0226

  Hot rolling · CPC title

• C21D9/46 Primary

  for sheet metals · CPC title