Steel sheet
A steel sheet includes: a predetermined chemical composition; and a steel structure represented by, in area %, first martensite in which two or more iron carbides each having a circle-equivalent diameter of 2 nm to 500 nm are contained in each lath: 20% to 95%, ferrite: 15% or less, retained austenite: 15% or less, and the balance: bainite, or second martensite in which less than two iron carbides each having a circle-equivalent diameter of 2 nm to 500 nm are contained in each lath, or the both of these, in which the total area fraction of ND//<111> orientation grains and ND//<100> orientation grains is 40% or less, and the content of solid-solution C is 0.44 ppm or more.
1. A steel sheet, comprising:
a chemical composition represented by,
in mass %,
C: 0.05% to 0.40%,
Si: 0.05% to 3.0%,
Mn: 1.5% to 3.5%,
Al: 1.5% or less,
N: 0.010% or less,
P: 0.10% or less,
S: 0.005% or less,
Nb: 0.00% to 0.04%,
Ti: 0.00% to 0.08%,
V and Ta: 0.0% to 0.3% in total,
Cr, Cu, Ni, Sn, and Mo: 0.0% to 1.0% in total,
B: 0.000% to 0.005%,
Ca: 0.000% to 0.005%,
Ce: 0.000% to 0.005%,
La: 0.000% to 0.005%, and
the balance: Fe and impurities; and
a steel structure represented by,
in area %,
first martensite in which two or more iron carbides each having a circle-equivalent diameter of 2 nm to 500 nm are contained in each lath: 20% to 95%,
ferrite: 15% or less,
retained austenite: 15% or less, and
the balance: bainite, or second martensite in which less than two iron carbides each having a circle-equivalent diameter of 2 nm to 500 nm are contained in each lath, or the both of these, wherein
the total area fraction of ND//<111> orientation grains and ND//<100> orientation grains is 37% or less,
the content of solid-solution C is 0.44 ppm or more,
the ND//<111> orientation grain is a crystal grain having a crystal orientation parallel to the normal direction of a sheet surface being a crystal orientation having a deviation from the <111> direction of 10° or less, and
the ND//<100> orientation grain is a crystal grain having a crystal orientation parallel to the normal direction of the sheet surface being a crystal orientation having a deviation from the <100> direction of 10° or less.
2. The steel sheet according to claim 1 , wherein
in the chemical composition,
V and Ta: 0.01% to 0.3% in total is established.
3. The steel sheet according to claim 1 , wherein
in the chemical composition,
Cr, Cu, Ni, Sn, and Mo: 0.1% to 1.0% in total is established.
4. The steel sheet according to claim 1 , wherein
in the chemical composition,
B: 0.0003% to 0.005% is established.
5. The steel sheet according to claim 1 , wherein one or more of:
Ca: 0.001% to 0.005%,
Ce: 0.001% to 0.005%, and
La: 0.001% to 0.005%,
are contained in the chemical composition.