Abstract: A hot-rolled steel sheet includes, as a chemical composition, by mass %, C: 0.030% to 0.10%, Mn: 0.5% to 2.5%, and Si+Al: 0.100% to 2.5%, in which the steel sheet has a microstructure including, by area fraction, ferrite: 80% or more, martensite: 3% to 15.0%, and pearlite: less than 3.0%, in which a number density of martensite having an equivalent circle diameter of 3 ?m or more at a position which is at a depth of ¼ of the steel sheet thickness from the surface of the steel sheet, is 5.0 pieces/10000 ?m2 or less, and the following Expression (1) is satisfied. R/DM2?1.00??Expression (1) Here, R is an average martensite interval (?m) defined by the following Expression (2), and DM is a martensite average diameter (?m). R={12.5×(?/6VM)0.5?(?)0.5}×DM??Expression (2) Here, VM is a martensite area fraction (%) and DM is the martensite average diameter (?m).

Abstract: To provide a panel whose surface rigidity can be improved appropriately in accordance with a load. Provided is a panel including: a load point to which a load is applied from the outside; and a protrusion that protrudes from a surface of the panel and is formed continuously or discontinuously around the load point. The protrusion intersects, at a plurality of positions, each of a plurality of virtual straight lines extending radially from the load point.

Abstract: [Object] To provide a shape inspection method, a shape inspection apparatus, and a program capable of adjusting the brightness and the thickness of a light-section line in a light-section image more simply and objectively.

Abstract: A pressed component includes an elongated top plate; ridge line portions at both short direction ends of the top plate; and vertical walls that face each other in a state extending from the ridge line portions, and the top plate includes a minimum portion, at which the Vickers hardness value is a minimum value, between one end and another end in the short direction of the top plate, and maximum portions, at which the Vickers hardness value is a maximum value, in each of a first range between the minimum portion and the one end, and a second range between the minimum portion and the other end.

Abstract: A rolled steel bar for machine structural use includes a predetermined chemical composition comprising, by mass %, C: 0.45% to 0.65%, Si: higher than 1.00% to 1.50%, Mn: higher than 0.40% to 1.00%, P: 0.005% to 0.050%, S: 0.020% to 0.100%, V: 0.08% to 0.20%, Ti: 0% to 0.050%; Ca: 0% to 0.0030%, Zr: 0% to 0.0030%, Te: 0% to 0.0030%, and a remainder including Fe and impurities, wherein the impurities include: Cr: 0.10% or lower, Al: lower than 0.01%, and N: 0.0060% or lower. In the rolled steel bar for machine structural use, K1 obtained from “K1=C+Si/7+Mn/5+1.54×V” is 0.95 to 1.05, K2 obtained from “K2=139?28.6×Si+105×Mn?833×S?13420×N” is more than 35, a Mn content and a S content satisfy Mn/S?8.0, and a total decarburized depth of a surface layer is 500 ?m or less.

Abstract: In forming a press-formed product that is made of a high-tensile steel sheet having a tensile strength of 390 MPa or more, and has a substantially gutter-shaped cross section and an outward continuous flange, wrinkling in ridges and cracking in the outward continuous flange are reduced. A method for manufacturing a press-formed product that is made of a high-tensile steel sheet of 390 MPa or more, and has a substantially gutter-shaped cross section and an outward continuous flange in at least one end in a predetermined direction includes a first step in which, after a first pad restrains at least a part of a portion to be formed into a gutter bottom in a forming material, a second pad restrains at least a part of the end of portions to be formed into ridges and subsequently carries out press forming.

Abstract: Provided is a negative electrode active material that can improve the discharge capacity per volume and charge-discharge cycle characteristics. The negative electrode active material according to the present embodiment contains an alloy phase. The alloy phase undergoes thermoelastic diffusionless transformation when releasing metal ions or occluding metal ions. The oxygen content of the negative electrode active material is not more than 5000 ppm in mass.

Abstract: Provided is a hot-formed member according to the present invention, having a predetermined chemical composition and having a metallographic microstructure containing austenite at an area ratio of 10 area % to 40 area % and in which total number density of particles of the austenite and martensite is equal to or greater than 1.0 number/?m2, in which tensile strength is from 900 MPa to 1300 MPa.

Abstract: There is provided an austenitic stainless steel for high-pressure hydrogen gas consisting, by mass percent, of C: 0.10% or less, Si: 1.0% or less, Mn: 3% or more to less than 7%, Cr: 15 to 30%, Ni: 10% or more to less than 17%, Al: 0.10% or less, N: 0.10 to 0.50%, and at least one kind of V: 0.01 to 1.0% and Nb: 0.01 to 0.50%, the balance being Fe and impurities, wherein in the impurities, the P content is 0.050% or less and the S content is 0.050% or less, the tensile strength is 800 MPa or higher, the grain size number (ASTM E112) is No. 8 or higher, and alloy carbo-nitrides having a maximum diameter of 50 to 1000 nm are contained in the number of 0.4/?m2 or larger in cross section observation.

Abstract: A cold-rolled steel sheet satisfies that an average pole density of an orientation group of {100}<011> to {223}<110> is 1.0 to 5.0, a pole density of a crystal orientation {332}<113> is 1.0 to 4.0, a Lankford-value rC in a direction perpendicular to a rolling direction is 0.70 to 1.50, and a Lankford-value r30 in a direction making an angle of 30° with the rolling direction is 0.70 to 1.50. Moreover, the cold-rolled steel sheet includes, as a metallographic structure, by area %, a ferrite and a bainite of 30% to 99% in total and a martensite of 1% to 70%.

Abstract: A resistance spot welding method including: a pulsation process of clamping a sheet assembly of two or more overlapped steel sheets including at least one high tensile steel sheet using a pair of welding electrodes that are connected to a spot welding power source employing an inverter direct current method, and performing plural repetitions of current passing and current pass stopping, while pressing the steel sheets with the welding electrodes; and a continuous current pass process in which, after the pulsation process, current is passed continuously for a longer period of time than a maximum current pass time of the pulsation process, while pressing the steel sheets with the welding electrodes.

Abstract: Provided is a composite particle which can improve the capacity per volume and charge-discharge cycle characteristics. The composite particle includes a plurality of specific particles and a binding material. The specific particle contains an alloy phase. The alloy phase undergoes thermoelastic diffusionless transformation when releasing metal ions or occluding metal ions. The binding material contains at least one of non-graphite carbon and a carbon precursor. The plurality of specific particles bind with each other via the binding material.

Abstract: An analyzing apparatus generates first displacement distribution data indicating a displacement distribution of a member caused by springback based on finite element model data, material physical property data, and stress distribution data; generates second displacement distribution data indicating an amount of displacement of the member in each of a plurality of, for example, all, natural vibration deformation modes based on the finite element model data and the material physical property data; obtains a degree of coincidence between the first displacement distribution data and each of the second displacement distribution data, and selects one or more natural vibration deformation modes based on the degree of coincidence, to determine a modified shape in which natural vibrations are increased, thereby bringing the member closer to a target shape.

Abstract: A brake disc of the present invention is a brake disc that stops the rotation of an axle when a brake pad is pressed on a surface of the brake disc, including a disc main body that is attached to a rotary body integrally rotating with the axle; and a plurality of build-up layers laminated on a surface of the disc main body, in which the build-up layers are laminated on the surface of the disc main body by means of laser metal deposition welding.

Abstract: There is provided a hot-rolled steel sheet in which a composition contains: in mass %, C: 0.01% to 0.2%; Si: 2.5% or less; Mn: 4.0% or less; P: 0.10% or less; S: 0.03% or less; Al: 0.001% to 2.0%; N: 0.01% or less; O: 0.01% or less; Ti: 0.01 to 0.30%; and the balance being composed of iron and impurities and a structure is composed of by volume fraction, 90% or more of tempered martensite with an average aspect ratio of 2 or less, or 90% or more in total of both tempered martensite and lower bainite.

Abstract: A bumper beam includes a first member, a second member, and an inner plate. The first member includes a top plate section, two vertical wall sections, and two flange sections. The two flange sections connect to the two vertical wall sections, respectively. The second member is plate-shaped, is joined to the two flange sections of the first member, and doses the gap between the two flange sections at least. The inner plate is joined to the two vertical wall sections of the first member and is disposed substantially in parallel with the second member in a space formed by the first member and the second member. Out of the first member and the second member, the second member is disposed facing the outside of a vehicle. Such a bumper beam has high energy absorption efficiency.

Abstract: A rolled steel bar for machine structural use includes a predetermined chemical composition comprising, by mass %, C: 0.45% to 0.65%, Si: higher than 1.00% to 1.50%, Mn: higher than 0.40% to 1.00%, P: 0.005% to 0.050%, S: 0.020% to 0.100%, V: 0.08% to 0.20%, Ti: 0% to 0.050%; Ca: 0% to 0.0030%, Zr: 0% to 0.0030%, Te: 0% to 0.0030%, and a remainder including Fe and impurities, wherein the impurities include: Cr: 0.10% or lower, Al: lower than 0.01%, and N: 0.0060% or lower. In the rolled steel bar for machine structural use, K1 obtained from “K1=C+Si/7+Mn/5+1.54×V” is 0.95 to 1.05, K2 obtained from “K2=139?28.6×Si+105×Mn?833×S?13420×N” is more than 35, K3 obtained from “K3=137×C?44.0×Si” is 10.7 or more, a Mn content and a S content satisfy Mn/S?8.0, and a total decarburized depth in a surface layer is 500 ?m or less.

Abstract: A primary object of the present invention is to provide a technique of avoiding occurrence of surface defects caused by an electromagnetic brake while checking internal defects with this electromagnetic brake, so that cleanliness of a cast steel can be improved compared with prior arts, and the present invention provides a method for continuously casting steel, the method comprising supplying molten steel into a mold while applying an electromagnetic brake to an outlet flow discharged from an outlet port of an immersion nozzle, wherein magnetic flux density (B) of the electromagnetic brake is within a range of the following (Formula 1): B min ? B ? B max , ? B min = 800 · ( D max D 0 ) 3 · ( H SEN H 0 ) ( v · sin ? ? ? ) , and ? ? B max = 3000 · ( D max D 0 ) 3 · ( H SEN H 0 ) ( v · sin ? ? ? ) 2 .

Abstract: A welded state monitoring system according to an aspect of the present invention is a welded state monitoring system used for plasma shielded electric resistance welding in which electric resistance welding is performed while irradiating a weld zone of a steel sheet with plasma, and is provided with a plasma irradiation device which irradiates the weld zone with plasma, a first image capturing device which captures an image of the weld zone from above and has an image sensor capable of detecting light having a wavelength of 850 nm or more, a first wavelength region limiting device which limits light incident on the first image capturing device to a wavelength region of 850 nm or more, and an image processing device which subjects the image captured by the first image capturing device to image processing and analyzes the welded state of the weld zone thereby being able to analyze the welded state without being affected by the plasma.

Abstract: A railway wheel includes: a wheel including a plate portion; and a brake disc including a circular plate portion whose front face side is a sliding surface, and a plurality of fin portions which are radially projected on a back face of the circular plate portion, wherein two of the brake discs are fastened in a region within the sliding surface. Regarding an area of a section crossing a space between the brake disc and the wheel along a circumferential direction, a minimum section portion in which the sectional area is minimum is present in a region formed by an outer peripheral surface of the circular plate portion and an inner peripheral surface of the rim portion, and the outer peripheral surface of the circular plate portion follows the inner peripheral surface of the rim portion in a region extending to the outer side from the minimum section portion.