Hot-stamping formed body
This hot-stamping formed body includes, as a chemical composition, by mass %: C: 0.15% or more and 0.50% or less; Si: 0.10% or more and 3.00% or less; Mn: 0.10% or more and 3.00% or less; P: less than 0.10%; S: less than 0.10%; N: less than 0.10%; Ti: 0.020% or more and 0.150% or less; B: 0.002% or more and 0.010% or less; optionally Al, Cr, Mo, Co, Ni, Cu, V, W, Ca, Mg, and REM; and a remainder including Fe and impurities, in which a microstructure of the hot-stamping formed body includes, by volume fraction, 85% or more of martensite and less than 15% of retained austenite, and in the microstructure, a standard deviation of a frequency distribution of nanohardnesses is 0.70 GPa or less, and an average grain size is 4.0 μm or less.
1 . A hot-stamping formed body comprising, as a chemical composition, by mass %:
C: 0.15% or more and 0.50% or less;
Si: 0.10% or more and 3.00% or less;
Mn: 0.10% or more and 3.00% or less;
P: less than 0.10%;
S: less than 0.10%;
N: less than 0.10%;
Ti: 0.020% or more and 0.150% or less;
B: 0.002% or more and 0.010% or less;
Al: 0% or more and 2.0% or less;
Nb: 0% or more and 0.150% or less;
Cr: 0% or more and 1.0% or less;
Mo: 0% or more and 1.0% or less;
Co: 0% or more and 2.0% or less;
Ni: 0% or more and 3.0% or less;
Cu: 0% or more and 1.0% or less;
V: 0% or more and 1.0% or less;
W: 0% or more and 1.0% or less;
Ca: 0% or more and 0.0100% or less;
Mg: 0% or more and 0.0100% or less;
REM: 0% or more and 0.0100% or less; and
a remainder including Fe and impurities,
wherein a microstructure of the hot-stamping formed body includes, by volume fraction, 85% or more of martensite and less than 15% of retained austenite, and
in the microstructure, a standard deviation of a frequency distribution of nanohardnesses is 0.70 GPa or less, and an average grain size is 4.0 μm or less.
2 . The hot-stamping formed body according to claim 1 , comprising, as the chemical composition, by mass %, one or more of:
Al: 0.0002% or more and 2.0% or less;
Nb: 0.010% or more and 0.150% or less;
Cr: 0.1% or more and 1.0% or less;
Mo: 0.1% or more and 1.0% or less;
Co: 0.1% or more and 2.0% or less;
Ni: 0.1% or more and 3.0% or less;
Cu: 0.1% or more and 1.0% or less;
V: 0.1% or more and 1.0% or less;
W: 0.1% or more and 1.0% or less;
Ca: 0.0010% or more and 0.0100% or less;
Mg: 0.0010% or more and 0.0100% or less; and
REM: 0.0010% or more and 0.0100% or less.
3 . The hot-stamping formed body according to claim 1 , wherein a surface of the hot-stamping formed body has an alloy layer.
4 . The hot-stamping formed body according to claim 2 ,
wherein a surface of the hot-stamping formed body has an alloy layer.