Abstract: 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 ?m or less.

Abstract: Provided is a frame member obtained by joining a first steel sheet member and a second steel sheet member at a spot-welding portion by spot welding. A cross-sectional region in which a cross section perpendicular to a longitudinal direction of the frame member is a closed cross section is formed, the first steel sheet member has a tensile strength of 1,900 MPa or more, and the spot-welding portion has a molten metal portion formed by the spot welding and a heat-affected portion adjacent to an outside of the molten metal portion. Average Vickers hardness HvAve at a measurement position corresponding to the first region on the virtual straight line and minimum Vickers hardness HvMin at a measurement position corresponding to the third region on the virtual straight line satisfy HvAve?HvMin?100.

Abstract: A hot stamped article having excellent shock absorption having a predetermined chemical composition, having a microstructure containing prior austenite having an average grain size of 3 ?m or less and further containing at least one of lower bainite, martensite, and tempered martensite in an area ratio of 90% or more, and having a grain boundary solid solution ratio Z defined by Z=(mass % of one or both of Nb and Mo at grain boundaries)/(mass % of one or both of Nb and Mo at time of melting) of 0.3 or more.

Abstract: This hot-stamping formed body has a predetermined chemical composition and has a metallographic structure consisting of, by area ratio, a total of 10% to 30% of ferrite and granular bainite and a remainder in microstructure consisting of one or more of martensite, bainite, and tempered martensite, and, in textures of a surface layer region and an inside region, ratios between a pole density of an orientation group consisting of {001}<1-10> to {001}<?1-10> and a pole density of an orientation group consisting of {111}<1-10> to {111}<?1-12> are controlled.

Abstract: These steel sheet for hot stamping and hot-stamping formed body have predetermined chemical composition and metallographic structures, and, in textures of a surface layer region and an inside region, ratios between a pole density of an orientation group consisting of {001}<1-10> to {001}<?1-10> and a pole density of an orientation group consisting of {111}<1-10> to {111}<?1-12> are controlled.

Abstract: A hot stamped body with high strength, good bendability and crack propagation resistance, consisting of: in mass %, C: 0.06% or more to less than 0.20%, Si: 0.010-1.00%, Mn: 0.80-2.00%, P: 0.100% or less, S: 0.010% or less, Al: 0.010-0.500%, N: 0.010% or less, Nb: more than 0.020% to 0.10% or less, Ti: 0-0.10%, V: 0-0.10%, Cr: 0-0.50%, Mo: 0-1.00%, B: 0-0.0100%, Ni: 0-0.50%, REM: 0-0.0100%, Mg: 0-0.010%, Ca: 0-0.0100%, and Co: 0-2.0%, with the balance: Fe and impurities, wherein a microstructure includes, in area fraction, ferrite: 5-50%, and martensite: 50-95%, a proportion of regions in the martensite where GAIQ values are 35000 or more to less than 45000 is 30 area % or more, and a maximum bending angle ? (deg) is 90 or more.

Abstract: A hot stamped body with high strength and good bendability, comprising a chemical composition consisting of: in mass %, C: 0.06% or more to less than 0.20%, Si: 0.010 to 1.00%, Mn: 1.20 to 3.00%, P: 0.100% or less, S: 0.010% or less, Al: 0.010 to 0.500%, N: 0.010% or less, Nb: 0.0010 to 0.020%, Ti: 0 to 0.10%, V: 0 to 0.10%, Cr: 0 to 0.50%, Mo: 0 to 1.00%, B: 0 to 0.0100%, Ni: 0 to 0.50%, REM: 0 to 0.0100%, Mg: 0 to 0.010%, Ca: 0 to 0.0100%, and Co: 0 to 2.0%, with the balance: Fe and impurities, wherein a microstructure includes martensite: 85% or more, a proportion of regions in the martensite where GAIQ values are 35000 or more to less than 45000 is 30 area % or more, and TS×?, is 105000 or more, and ? is 75 or more.

Abstract: 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 ?m or more is 50/mm2 or less.

Abstract: A steel sheet for hot stamping use used as a material for a hot stamped article excellent in strength or bending deformability, having a predetermined chemical composition, having a microstructure containing at least one of lower bainite, martensite, and tempered martensite in an area ratio of 90% or more, having an X-ray random intensity ratio of {112}<111> of the crystal grains forming the above lower bainite, martensite, or tempered martensite of 2.8 or more, having a number density of grain size 50 nm or less cementite or epsilon carbides in the microstructure of 1×1016/cm3 or more, and having a grain boundary solid solution ratio Z defined by Z=(mass % of one or both of Nb and Mo at grain boundaries)/(mass % of one or both of Nb and Mo at time of melting) of 0.4 or more.

Abstract: 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 ?m or more is 50/mm2 or less.

Abstract: A hot-stamping formed body has a predetermined chemical composition, in which an average grain size of prior austenite grains in a microstructure is 5.0 ?m or less, and an average Mn concentration at grain boundaries of the prior austenite grains is 1.0 mass % or less. The hot-stamping formed body may be provided with a plating layer on the surface thereof, or may have a softened region in a portion thereof.

Abstract: A hot stamped article excellent in strength having a predetermined composition, having an average crystal grain size of prior austenite of 3 ?m or less, containing at least one of lower bainite, martensite, and tempered martensite in an area rate of 90% or more, and having a grain boundary solid solution ratio Z, defined by Z=(mass % of one or both of Nb and Mo at the grain boundaries)/(mass % of one or more of Nb and Mo at time of dissolution) of 0.3 or more.

Abstract: A hot stamped article of high strength steel sheet excellent in bending deformability having a predetermined chemical composition, having an area rate of 90% or more of the microstructures of the steel sheet comprised of one or more of lower bainite, martensite, and tempered martensite, and having a ratio of the length of grain boundaries with a rotational angle about a rotational axis of the <011> direction of the crystal grains of the lower bainite, martensite, and tempered martensite of 15° or more with respect to the length of grain boundaries with a rotational angle of 5° to 75° of 80% or more.

Abstract: A steel sheet for hot stamping use used as a material for a hot stamped article excellent in strength or bending deformability, having a predetermined chemical composition, having a microstructure containing at least one of lower bainite, martensite, and tempered martensite in an area ratio of 90% or more, having an X-ray random intensity ratio of {112}<111> of the crystal grains forming the above lower bainite, martensite, or tempered martensite of 2.8 or more, having a number density of grain size 50 nm or less cementite or epsilon carbides in the microstructure of 1×1016/cm3 or more, and having a grain boundary solid solution ratio Z defined by Z=(mass % of one or both of Nb and Mo at grain boundaries)/(mass % of one or both of Nb and Mo at time of melting) of 0.4 or more.

Abstract: A hot stamped article excellent in strength having a predetermined composition, having an average crystal grain size of prior austenite of 3 ?m or less, containing at least one of lower bainite, martensite, and tempered martensite in an area rate of 90% or more, and having a grain boundary solid solution ratio Z, defined by Z=(mass % of one or both of Nb and Mo at the grain boundaries)/(mass % of one or more of Nb and Mo at time of dissolution) of 0.3 or more.

Abstract: A hot stamped article having excellent shock absorption having a predetermined chemical composition, having a microstructure containing prior austenite having an average grain size of 3 ?m or less and further containing at least one of lower bainite, martensite, and tempered martensite in an area ratio of 90% or more, and having a grain boundary solid solution ratio Z defined by Z=(mass % of one or both of Nb and Mo at grain boundaries)/(mass % of one or both of Nb and Mo at time of melting) of 0.3 or more.

Abstract: A hot stamped article of high strength steel sheet excellent in bending deformability having a predetermined chemical composition, having an area rate of 90% or more of the microstructures of the steel sheet comprised of one or more of lower bainite, martensite, and tempered martensite, and having a ratio of the length of grain boundaries with a rotational angle about a rotational axis of the <011> direction of the crystal grains of the lower bainite, martensite, and tempered martensite of 15 or more with respect to the length of grain boundaries with a rotational angle of 5° to 75° of 80% or more.

Abstract: The present invention, in consideration of the problems in the prior art, provides a hot stamped body simultaneously achieving the high bendability and high ductility for realizing impact resistance and also hydrogen embrittlement resistance and kept down in scattering in hardness. The hot stamped body according to the present invention is provided with a middle part in sheet thickness and a softened layer arranged at both sides or one side of the middle part in sheet thickness.

Abstract: There is provided a hot stamped body including a middle part in sheet thickness and a surface layer arranged at both sides or one side of the middle part in sheet thickness, further including an intermediate layer formed between the middle part in sheet thickness and each surface layer so as to adjoin them, wherein the middle part in sheet thickness has a predetermined composition, the middle part in sheet thickness has a hardness of 500 Hv or more and 800 Hv or less, the surface layer has a hardness change ?H1 in the sheet thickness direction of 10 Hv or more and less than 200 Hv, and the intermediate layer has a hardness change ?H2 in the sheet thickness direction of 50 Hv or more and less than 200 Hv.