Abstract: Provided is a crash box having improved robustness, wherein an angle of the pair of corner portions is set to 90° or larger and 150° or smaller, an angle of the another pair of corner portions is set to 30° or larger and 90° or smaller, one or more inwardly convex trench portions extending in a longitudinal direction are provided, a cross-sectional peripheral length of the tubular body in the one end side is shorter than a cross-sectional peripheral length of the tubular body in the other end side, an aspect ratio between the longest one and the shortest one of diagonal lines of a polygon changes depending on a position on the axial direction of the tubular body, and overall sides on the cross section in the one end are formed in parallel to the opposite sides on the cross section in the other end.

Abstract: A press-formed body (15) made of a high-tensile strength steel sheet of 390 MPa or more including a groove bottom part (15a), ridge line parts (15b, 15b) continuous to the groove bottom part (15a), and side wall parts (15c, 15c) continuous to the ridge line parts (15b, 15b), and in which an outward flange (16) is formed at an end part in a longitudinal direction is manufactured by a press-forming apparatus including a punch (11), a die (12), and a pad (14) which presses and binds a press-forming material (13) to the punch (11). At a press-forming time, the pad (14) binds a part to be formed into the groove bottom part (15a) and a part having a length of one-third or more of a cross-sectional peripheral length of the ridge line part (15b) starting from a connecting part with the groove bottom part (15a) from among a part to be formed into the ridge line part (15b) in a vicinity of the outward flange (16) at the press-forming material (13).

Abstract: A steel material contains: by mass %, C: greater than 0.05% to 0.18%; Mn: 1% to 3%; Si: greater than 0.5% to 1.8%; Al: 0.01% to 0.5%; N: 0.001% to 0.015%; one or both of V and Ti: 0.01% to 0.3% in total; Cr: 0% to 0.25%; Mo: 0% to 0.35%; a balance: Fe and impurities; and 80% or more of bainite by area %, and 5% or more in total of one or two or more selected from a group consisting of ferrite, martensite and austenite by area %, in which an average block size of the above-described bainite is less than 2.0 ?m, an average grain diameter of all of the above-described ferrite, martensite and austenite is less than 1.0 ?m, an average nanohardness of the above-described bainite is 4.0 GPa to 5.0 GPa, and MX-type carbides each having a circle-equivalent diameter of 10 nm or more exist with an average grain spacing of 300 nm or less therebetween.

Abstract: A steel sheet suitable as a starting material for a vehicle impact absorbing member with high absorption of impact energy and resistance to cracking contains, by mass %, C: 0.08-0.30%, Mn: 1.5-3.5%; Si+Al: 0.50-3.0%, P: 0.10% or less, S: at most 0.010%, and N: at most 0.010%, and optionally, one or more types selected from Cr: at most 0.5%, Mo: at most 0.5%, B: at most 0.010%, Ti: less than 0.04%, Nb: less than 0.030%, V: less than 0.5%, Ca: at most 0.010%, Mg: at most 0.010%, REM: at most 0.050%, and Bi: at most 0.050%. The microstructure contains, by area %, bainite: more than 50%, martensite: 3-30%, and retained austenite: 3-15%, the remainder comprising ferrite having an average grain diameter of less than 5 mm. The product of uniform elongation and hole expansion ratio is at least 300%2 and 5% effective flow stress is at least 900 MPa.

Abstract: A steel material having a chemical composition of, by mass %, C: greater than 0.05% to 0.2%, Mn: 1% to 3%, Si: greater than 0.5% to 1.8%, Al: 0.01% to 0.5%, N: 0.001% to 0.015%, Ti or a sum of V and Ti: greater than 0.1% to 0.25%, Ti: 0.001% or more, Cr: 0% to 0.25%, Mo: 0% to 0.35%, and a balance: Fe and impurities, includes a steel structure being a multi-phase structure having a main phase made of ferrite of 50 area % or more, and a second phase containing one or two or more selected from a group consisting of bainite, martensite and austenite, in which an average nanohardness of the above-described second phase is less than 6.

Abstract: In a floor cross member configured by a web surface (4a) as the top surface, a ridge part (4b) contiguous to the web surface (4a), and a vertical wall surface (4c) contiguous to the ridge part (4b), having a tensile strength of 440 MPa or larger, flanges (4e) are formed at both longitudinal ends continuously around at least the web surface (4a), the ridge part (4b) and the vertical wall surface (4c), and the floor cross member (4) is connected through the flanges (4e) to a tunnel part (2a) and to a side sill (3). The flange (4e) has a flange width lfc, at the center in the perimeter direction of the curved part (4e-2), not smaller than the minimum flange width lfs of the curved part (4e-2). Accordingly, a vehicle body, which is suppressed in deformation of the floor cross member (4) and improved in the torsional rigidity, is successfully provided.

Abstract: A front floor panel for an automotive body as a lightweight sheet can be reliably press-formed without a press forming loads becoming excessively large, can have desired stiffness, and noise and vibration characteristics for all directions since there is little stiffness anisotropy. The front floor panel includes a floor tunnel formed in a center in an automotive width direction to be oriented to a longitudinal direction, upright flanges disposed left and right formed at a left and right end portions in the automotive width direction to be joined to side sills, and a left and right plane portions formed between the upright flanges disposed left and right and a left and right longitudinal wall portions of the floor tunnel. In loop-shaped areas including outer edge portions of the plane portions, convex-concave parts in specific shapes are formed, and remaining areas excluding the loop-shaped areas are formed into flat sheet shapes.

Abstract: Tissue array production method enables even roll-shaped tissue pieces having various diameters to be steadily fixed to a substrate block is provided. In a method in which roll-shaped tissue pieces formed by rolling sheet-like tissue pieces in the shape of a roll are arranged on a substrate in an array form, a tissue array is produced by placing a holding member which holds a plurality of roll-shaped tissue pieces so that their axis directions are vertically directed in a container into which a melted embedding medium is poured for its accumulation, to hold the respective roll-shaped tissue pieces in the holding member; pouring the embedding medium into the container, to form a substrate block constituted so that the plurality of roll-shaped tissue pieces is arranged in the array form; and slicing the substrate block so that the roll-shaped tissue pieces are ring-shaped.

Abstract: A formed member is provided which can be manufactured at a low cost, which has excellent dimensional accuracy, which has excellent axial crushing properties and three-point bending properties, which has excellent bending stiffness and torsional stiffness, and which is suitable for use in a component of an automobile. The formed member (20) has a reinforcing member (35) which is joined by a weld (40) provided on a ridge portion (28). It is manufactured by joining a flat sheet blank and a flat sheet reinforcing member (35) by a weld (40) and performing bending so that the weld (40) becomes a ridge portion (28).

Abstract: The invention provides a method for forming tissue pieces which allows stable and accurate winding around a core rod in rolling a sheet-like tissue piece, and a device therefor. In the tissue pieces used as each tissue piece in a tissue array obtained by arranging the tissue pieces on a substrate in an array form, the method for forming a roll-shaped tissue piece 6 obtained by rolling a sheet-like tissue piece 8 is characterized by the facts that the sheet-like tissue piece 8 is produced by slicing a tissue block 5 obtained by embedding the tissues with an embedding medium, the sheet-like tissue piece 8 is placed on a mounting block 12, peeling means 13 which easily enables peeling of the tissue piece 8 from the mounting block 12 is applied between the mounting block 12 and the tissue piece 8, and the tissue piece 8 is wound around a core rod 11 while heating the tissue piece 8 on the mounting block 12.

Abstract: A tissue array production method which enables even roll-shaped tissue pieces having various diameters to be steadily fixed to a substrate block is provided. In the tissue array production method in which roll-shaped tissue pieces 6 formed by rolling sheet-like tissue pieces 8 in the shape of a roll are arranged on a substrate in an array form, the tissue array is produced by placing a holding member 16 which holds a plurality of roll-shaped tissue pieces 6 so that their axis directions are vertically directed in a container 10 into which a melted embedding medium is poured for its accumulation, to hold the respective roll-shaped tissue pieces 6 in the holding member 16; by pouring the embedding medium into the container 10, to form a substrate block 40 constituted so that the plurality of roll-shaped tissue pieces 6 is arranged in the array form; and by slicing the substrate block 40 so that the roll-shaped tissue pieces 6 are ring-shaped, to place the sliced pieces on the substrate.

Abstract: A crash energy absorption member is provided which has excellent crash energy absorbing properties with the ability of repeated buckling in a stable manner, a high average load at the time of collapse, and the maximum load which is within a range which does not break other members. It is a crash energy absorption member which preferably has a transverse cross-sectional shape of an octagon and which is intended for absorbing impact energy by buckling in the lengthwise direction into a shape of bellows when it receives an impact load. With respect to at least one side forming the transverse cross-sectional shape, when the angle formed by the two sides which adjoin the opposing ends of the one side is ?, the relationship between the length L1 of the one side and the distance L2 between the two furthest ends of the two sides interposing the one side satisfies the following equation: 0<L1/L2<1/{2×sin(?/2)+1}.

Abstract: A crash energy absorption member capable of reducing the initial load without provision of a crushing bead and capable of achieving a sufficient amount of shock absorption with stable buckling behavior. The crash energy absorption member is formed from a tubular body which has a length L and a polygonal transverse cross-sectional shape with 2n corners due to having 2n ridge lines (wherein n is a natural number greater than or equal to 3) and 2n surfaces partitioned by these 2n ridge lines, and which absorbs impact energy by buckling when an impact load is applied to one end in the axial direction towards the other end, characterized in that some of the 2n ridge lines only exist in a region which extends from a position spaced by a distance h in the axial direction from the one end to the other end, and if the number of the remaining ridge lines which have a length L is m, the following equations are satisfied: h?L×0.30 ??(1) 4?m?2×(n?1).

Abstract: A crash energy absorption member formed from a tubular body for absorbing impact energy by buckling when it receives an impact load in the axial direction from one end in the axial direction. It has a transverse cross-sectional shape along at least a portion in the axial direction which is a closed cross section having a plurality of vertices in which there is no flange on the outside of the closed cross section, and in a region of at least one side of a basic cross section formed from the largest outline obtained by connecting a portion of the plurality of vertices by straight lines, a groove which is recessed towards the inside of the outline is provided in a location other than at an end point of the side. Thus, the crash energy absorption member can achieve a prescribed amount of shock absorption by stably buckling in the axial direction without bending and without an increase in weight due to the addition of a partition or due to an increase in plate thickness.

Abstract: A crash energy absorption member formed from a tubular body for absorbing impact energy by buckling when it receives an impact load in the axial direction from one end in the axial direction. It has a transverse cross-sectional shape along at least a portion in the axial direction which is a closed cross section having a plurality of vertices in which there is no flange on the outside of the closed cross section, and in a region of at least one side of a basic cross section formed from the largest outline obtained by connecting a portion of the plurality of vertices by straight lines, a groove which is recessed towards the inside of the outline is provided in a location other than at an end point of the side. Thus, the crash energy absorption member can achieve a prescribed amount of shock absorption by stably buckling in the axial direction without bending and without an increase in weight due to the addition of a partition or due to an increase in plate thickness.

Abstract: A crash energy absorption member is provided which has excellent crash energy absorbing properties with the ability of repeated buckling in a stable manner, a high average load at the time of collapse, and the maximum load which is within a range which does not break other members. It is a crash energy absorption member which preferably has a transverse cross-sectional shape of an octagon and which is intended for absorbing impact energy by buckling in the lengthwise direction into a shape of bellows when it receives an impact load. With respect to at least one side forming the transverse cross-sectional shape, when the angle formed by the two sides which adjoin the opposing ends of the one side is ?, the relationship between the length L1 of the one side and the distance L2 between the two firthest ends of the two sides interposing the one side satisfies the following equation: 0<L1/L2<1/{2×sin(?/2)+1}.

Abstract: A crash energy absorption member capable of reducing the initial load without provision of a crushing bead and capable of achieving a sufficient amount of shock absorption with stable buckling behavior. The crash energy absorption member is formed from a tubular body which has a length L and a polygonal transverse cross-sectional shape with 2n corners due to having 2n ridge lines (wherein n is a natural number greater than or equal to 3) and 2n surfaces partitioned by these 2n ridge lines, and which absorbs impact energy by buckling when an impact load is applied to one end in the axial direction towards the other end, characterized in that some of the 2n ridge lines only exist in a region which extends from a position spaced by a distance h in the axial direction from the one end to the other end, and if the number of the remaining ridge lines which have a length L is m, the following equations are satisfied: h?L×0.30 ??(1) 4?m?2×(n?1) ??(2).

Abstract: A method of manufacturing a high strength steel sheet containing, in mass %, C: 0.02 to 0.04%, Si: at most 0.4%, Mn: 0.5-3.0%, P: at most 0.15%, S: at most 0.03%, Al: at most 0.50%, N: at most 0.01%, and Mo: 0.01-1.0%. The method includes performing hot rough rolling either directly or after heating to a temperature of at most 1300° C., commencing hot finish rolling either directly or after reheating or holding, completing finish rolling at a temperature of at least 780° C., performing coiling after cooling to a temperature of 750° C. or below at an average cooling rate of at least 3° C./second, heating to an annealing temperature of at least 700° C. and then cooling to a temperature of 600° C. or below at an average cooling rate of at least 3° C./second, then holding in a temperature range of 450-600° C. for at least 10 seconds, and performing hot dip galvanizing after cooling.

Abstract: A steel for forming a high strength steel sheet contains, in mass %, C: at most 0.04%, Si: at most 0.4%, Mn: 0.5-3.0%, P: at most 0.15%, S: at most 0.03%, Al: at most 0.50%, N: at most 0.01%, and Mo: 0.01-1.0%. Steel sheet formed from the steel is suitable for use as automotive panels.

Abstract: A steel for forming a high strength steel sheet contains, in mass %, C: at most 0.04%, Si: at most 0.4%, Mn: 0.5-3.0%, P: at most 0.15%, S: at most 0.03%, Al: at most 0.50%, N: at most 0.01%, and Mo: 0.01-1.0%. Steel sheet formed from the steel is suitable for use as automotive panels.