Hot-rolled steel sheet
This hot-rolled steel sheet has a predetermined chemical composition, in a microstructure, in terms of area %, residual austenite is less than 3.0%, ferrite is 15.0% or more and less than 60.0%, and pearlite is less than 5.0%, an E value that indicates periodicity of the microstructure is 10.7 or more, and an I value that indicates uniformity of the microstructure is less than 1.020, a standard deviation of a Mn concentration is 0.60 mass % or less, and a tensile strength is 980 MPa or more.
1 . A hot-rolled steel sheet comprising, in terms of mass %, as a chemical composition:
C: 0.050% to 0.250%;
Si: 0.05% to 3.00%;
Mn: 1.00% to 4.00%;
one or more of Ti, Nb, and V: 0.060% to 0.500% in total;
sol. Al: 0.001% to 2.000%;
P: 0.100% or less;
S: 0.0300% or less;
N: 0.1000% or less;
O: 0.0100% or less;
Cu: 0% to 2.00%;
Cr: 0% to 2.00%;
Mo: 0% to 1.00%;
Ni: 0% to 2.00%;
B: 0% to 0.0100%;
Ca: 0% to 0.0200%;
Mg: 0% to 0.0200%;
REM: 0% to 0.1000%;
Bi: 0% to 0.020%;
one or more of Zr, Co, Zn, and W: 0% to 1.00% in total;
Sn: 0% to 0.05%; and
a remainder comprising Fe and impurities,
wherein, in a microstructure,
in terms of area %, residual austenite is less than 3.0%, ferrite is 15.0% or more and less than 60.0%, and pearlite is less than 5.0%,
an E value that indicates periodicity of the microstructure is 10.7 or more, and an I value that indicates uniformity of the microstructure is less than 1.020,
a standard deviation of a Mn concentration is 0.60 mass % or less, and
a tensile strength is 980 MPa or more.
2 . The hot-rolled steel sheet according to claim 1 ,
wherein an average crystal grain size of a surface layer is less than 3.0 m.
3 . The hot-rolled steel sheet according to claim 1 , further comprising, in terms of mass %, one or more of, as the chemical composition:
Cu: 0.01% to 2.00%;
Cr: 0.01% to 2.00%;
Mo: 0.01% to 1.00%;
Ni: 0.02% to 2.00%;
B: 0.0001% to 0.0100%;
Ca: 0.0005% to 0.0200%;
Mg: 0.0005% to 0.0200%;
REM: 0.0005% to 0.1000%; and
Bi: 0.0005% to 0.020%.
4 . The hot-rolled steel sheet according to claim 2 , further comprising, in terms of mass %, one or more of, as the chemical composition:
Cu: 0.01% to 2.00%;
Cr: 0.01% to 2.00%;
Mo: 0.01% to 1.00%;
Ni: 0.02% to 2.00%;
B: 0.0001% to 0.0100%;
Ca: 0.0005% to 0.0200%;
Mg: 0.0005% to 0.0200%;
REM: 0.0005% to 0.1000%; and
Bi: 0.0005% to 0.020%.