Hot-stamping formed body
A hot-stamping formed body has a predetermined chemical composition and a microstructure including, by area ratio, 90% to 100% of martensite and 0% to 10% of a remainder in the microstructure. In the microstructure, a region in which an average GAIQ value in a unit grain is 60,000 or more is 30 area % or more, and a number density of carbides having a circle equivalent diameter of 0.20 μm or more is 50/mm 2 or less.
1. A hot-stamping formed body comprising, as a chemical composition, by mass %:
C: 0.20% or more and less than 0.70%;
Si: 0.010% to 1.30%;
Mn: less than 0.50%;
P: 0.100% or less;
S: 0.0100% or less;
sol. Al: 0.0010% to 0.500%;
N: 0.0100% or less;
Ti: 0.010% to 0.100%;
Cr: 0.010% to 0.80%;
B: 0.0005% to 0.0100%;
Mo: 0.10% to 1.00%;
Co: 0.10% to 4.00%;
Nb: 0% to 0.100%;
V: 0% to 0.100%;
Ni: 0% to 0.50%;
REM: 0% to 0.0100%;
Mg: 0% to 0.0100%;
Ca: 0% to 0.0100%; and
a remainder consisting of Fe and impurities,
wherein a microstructure of the hot-stamping formed body includes, by area ratio, 90% to 100% of martensite and 0% to 10% of a crystalline phase other than the martensite,
in the microstructure,
a region in which an average grain average image quality value in a unit grain is 60,000 or more is 30 area % or more, and
a number density of carbides having a circle equivalent diameter of 0.20 μm or more is 50/mm 2 or less.
2. The hot-stamping formed body according to claim 1 comprising, as the chemical composition, by mass %, one or two or more elements of:
Nb: 0.010% to 0.100%;
V: 0.001% to 0.100%;
Ni: 0.001% to 0.50%;
REM: 0.0010% to 0.0100%;
Mg: 0.0010% to 0.0100%; and
Ca: 0.0010% to 0.0100%.
3. The hot-stamping formed body according to claim 2 , further comprising:
a plating layer on a surface layer of the hot-stamping formed body.
4. The hot-stamping formed body according to claim 2 ,
wherein a portion of the hot-stamping formed body has a softened region.
5. The hot-stamping formed body according to claim 1 , further comprising:
a plating layer on a surface layer of the hot-stamping formed body.
6. The hot-stamping formed body according to claim 5 ,
wherein a portion of the hot-stamping formed body has a softened region.
7. The hot-stamping formed body according to claim 1 ,
wherein a portion of the hot-stamping formed body has a softened region.
8. A hot-stamping formed body comprising, as a chemical composition, by mass %:
C: 0.20% or more and less than 0.70%;
Si: 0.010% to 1.30%;
Mn: less than 0.50%;
P: 0.100% or less;
S: 0.0100% or less;
sol. Al: 0.0010% to 0.500%;
N: 0.0100% or less;
Ti: 0.010% to 0.100%;
Cr: 0.010% to 0.80%;
B: 0.0005% to 0.0100%;
Mo: 0.10% to 1.00%;
Co: 0.10% to 4.00%;
Nb: 0% to 0.100%;
V: 0% to 0.100%;
Ni: 0% to 0.50%;
REM: 0% to 0.0100%;
Mg: 0% to 0.0100%;
Ca: 0% to 0.0100%; and
a remainder comprising Fe and impurities,
wherein a microstructure of the hot-stamping formed body includes, by area ratio, 90% to 100% of martensite and 0% to 10% of a crystalline phase other than the martensite,
in the microstructure,
a region in which an average grain average image quality value in a unit grain is 60,000 or more is 30 area % or more, and
a number density of carbides having a circle equivalent diameter of 0.20 μm or more is 50/mm 2 or less.