Abstract: A steel plate has excellent strength and toughness in a mid-thickness part thereof, despite having a plate thickness of 100 mm or greater. The steel plate has a chemical composition containing specific amounts of C, Si, Mn, P, S, Cr, Ni, Al, N, B, and 0, with the balance being Fe and incidental impurities, and having an equivalent carbon content Cer of 0.65 or greater. The steel plate has a yield strength of 620 MPa or greater, a plate thickness of 100 mm or greater, and has a microstructure in which prior ? grain size in a mid-thickness part of the steel plate has a maximum value, expressed as an equivalent circle diameter, of 150 ?m or less, and a total area ratio of martensite and bainite in the mid-thickness part is 80% or greater.

Abstract: A steel plate includes a predetermined chemical composition, in which B is controlled to be less than 0.0003%, and the balance is Fe and incidental impurities. The steel plate also includes precipitates containing Ti, Nb, and Mo and having a mean particle size of 20 nm or less, the relationship [Nb]/([Ti]+[Nb]+[Mo])?0.3 being satisfied, where [Ti] is the Ti content, [Nb] is the Nb content, and [Mo] is the Mo content, thereby providing a thick, high tensile strength steel plate that is suitable for use in steel structures such as marine structures, ships, pressure vessels, and penstocks, has a yield stress (YS) of 460 MPa or greater, and has excellent low-temperature toughness of the heat-affected zone in a multilayer weld (CTOD property) and excellent strength and toughness after Post Weld Heat Treatment (PWHT property).

Abstract: Provided is high strength steel for springs that, compared to conventional high strength steel for springs, has excellent decarburization resistance and scale exfoliation property, by optimization of the added amounts of C, Si, Mn, and Cr as well as of Sb and Sn. The steel for springs contains C: more than 0.45 mass % and less than 0.65 mass %, Si: 0.15 mass % or more and 0.70 mass % or less, Mn: 0.10 mass % or more and 1.00 mass % or less, Cr: 0.20 mass % or more and 1.50 mass % or less, P: 0.025 mass % or less, S: 0.025 mass % or less, O: 0.0015 mass % or less, Sb: 0.010 mass % or more and less than 0.030 mass %, and Sn: 0.010 mass % or more and 0.030 mass % or less, under predetermined conditions.

Abstract: A pearlitic rail includes a composition including in % by mass: 0.70% to 0.90% of C; 0.1% to 1.5% of Si; 0.01% to 1.5% of Mn; 0.001% to 0.035% of P; 0.0005% to 0.030% of S; 0.1% to 2.0% of Cr, remainder of the composition consisting of Fe and inevitable impurities. Surface hardness of a rail top is not less than HB 430, and hardness at a depth of 25 mm from a surface of the rail top is not less than HB 410.

Abstract: A steel plate has a chemical composition containing, by mass %, C: 0.03% or more and 0.10% or less, Si: 0.05% or more and 0.50% or less, Mn: 1.00% or more and 2.00% or less, P: 0.015% or less, S: 0.005% or less, Mo: 0.20% or less (including 0%), Nb: 0.01% or more and 0.05% or less, and the balance being Fe and inevitable impurities, and, if desired, containing, by mass %, one or more of Al: 0.005% or more and 0.1% or less, Cu: 1.00% or less, Ni: 1.00% or less, Cr: 0.50% or less, and V: 0.05% or less, in which Pcm* (%) (=C+Si/30+(Mn+Cu+Cr)/20+Ni/60+Mo/2+V/10) is 0.20 or less. The steel plate has a volume fraction of bainite in a base material of 50% or more, and has a volume fraction of island martensite (MA) in a coarse-grain region reheated in a dual-phase temperature range of 5.0% or less.

Abstract: Provided are a thick steel plate with which a welded joint having good CTOD property is formed by low-to-medium heat input multipass welding and a method for producing the thick steel plate. The steel plate has a composition containing, by mass, C: 0.03% to 0.10%, Si: 0.5% or less, Mn: 1.0% to 2.0%, P: 0.015% or less, S: 0.0005% to 0.0050%, Al: 0.005% to 0.060%, Ni: 0.5% to 2.0%, Ti: 0.005% to 0.030%, N: 0.0015% to 0.0065%, O: 0.0010% to 0.0050%, Ca: 0.0005% to 0.0060%, and, as needed, one or more elements such as Cu. Ti/N, Ceq, Pcm, and ACR each fall within the specific range. The effective crystal grain size of the base metal at the center of the plate in the thickness direction is 20 ?m or less. A specific amount of a composite inclusion including a sulfide containing Ca and Mn and an oxide containing Al having an equivalent circular diameter of 0.1 ?m or more is present at the ¼-thickness position and the ½-thickness position of the plate.

Abstract: There is provided a thick steel plate having good multipass weld joint CTOD characteristics for low to medium heat input and a method for manufacturing the thick steel plate. A steel plate containing, on a mass percent basis, C: 0.03% to 0.12%, Si: 0.5% or less, Mn: 1.0% to 2.0%, P: 0.015% or less, S: 0.0005% to 0.0050%, Al: 0.005% to 0.060%, Ni: 0.5% to 2.0%, Ti: 0.005% to 0.030%, N: 0.0015% to 0.0065%, O: 0.0010% to 0.0050%, Ca: 0.0005% to 0.0060%, and optionally one or two or more of Cu and the like, wherein Ti/N, Ceq, Pcm, and ACR are in particular ranges, a base material of the plate has an effective grain size of 20 ?m or less at half the thickness of the plate, and the plate contains a particular number of complex inclusions at ¼ and ½ of the thickness of the plate, the complex inclusions being composed of a sulfide containing Ca and Mn and an oxide containing Al and having an equivalent circular diameter of 0.1 ?m or more.

Abstract: A thick, high-toughness high-strength steel plate has excellent strength and toughness in the central area through the plate thickness. The thick steel plate has a specific chemical composition and includes a microstructure having, throughout an entire region in the plate thickness direction, an average prior austenite grain size of not more than 50 ?m and a martensite and/or bainite phase area fraction of not less than 80%. A continuously cast slab having the specific chemical composition is heated to 1200° C. to 1350° C., hot worked with a strain rate of not more than 3/s and a cumulative working reduction of not less than 15%, and thereafter hot rolled and heat treated.

Abstract: A punch die includes: a punch body including a punch edge portion at a lower end portion along an axis, a key projecting from an outer periphery, and a punch driver at an upper portion along the axis; a punch guide including an inner hollow elongated along the axis and receiving the punch body to be movable along the axis, and a keyway formed on an internal periphery of the inner hollow to extend along the axis and mesh with the key; a retainer collar rotatably combined with the punch guide at an upper end along the axis and around the axis, the punch driver passing through the retainer collar to be movable along the axis; and a punch head screwed in an upper end portion along the axis of the punch driver to regulate a position of the punch driver.

Abstract: A passenger's weight measurement device for a vehicle seat includes an upper rail provided on a lower rail that is fixable to a vehicle floor, the upper rail being movable in at least one of rear and front directions; a load sensor fixed onto the upper rail; and a frame provided on the load sensor and below the vehicle seat. In plan view, the load sensor protrudes from the frame in at least one of left and right directions.

Abstract: A punch die includes: a punch body including a punch edge portion at a lower end portion along an axis, a key projecting from an outer periphery, and a punch driver at an upper portion along the axis; a punch guide including an inner hollow elongated along the axis and receiving the punch body to be movable along the axis, and a keyway formed on an internal periphery of the inner hollow to extend along the axis and mesh with the key; a retainer collar rotatably combined with the punch guide at an upper end along the axis and around the axis, the punch driver passing through the retainer collar to be movable along the axis; and a punch head screwed in an upper end portion along the axis of the punch driver to regulate a position of the punch driver.

Abstract: A vehicle seat includes a load sensor for measuring a load applied from an occupant and a seat cushion frame, wherein the seat cushion frame comprises right and left side frames extending in a front-and-rear direction, the load sensor is attached to the seat cushion frame, and a concave portion is formed in at least one of the right and left side frames at a position opposite to the load sensor.

Abstract: A vehicle seat includes a load sensor that is configured to measure a load applied from an occupant and that has a rod extending therefrom, a seat cushion frame that includes right and left side frames that extend along a front-rear axis, and a bracket member attaching the load sensor to at least one of the right and left side frames. A lower surface of the at least one side frame has a concave part opening downward. At least a part of the load sensor is lower than the concave part, and the load sensor is closer to a center of the vehicle seat than the concave part.

Abstract: A vehicle seat includes a load sensor that is configured to measure a load applied from an occupant, a seat cushion frame that includes a right side frame and a left side frame, and a pan frame. At least one of the right and left side frames includes an upper-side protruding section provided at an upper part of the at least one side frame and a lower-side protruding section provided at a lower part of the at least one side frame, the upper-side protruding section and the lower-side protruding section extending along a right-left axis. At least one load sensor attachment bracket of the vehicle seat is attached to the at least one side frame between the upper-side protruding section and the lower-side protruding section.

Abstract: A vehicle seat includes a load sensor that is configured to measure a load applied from an occupant and a seat cushion frame that includes a right side frame and a left side frame. The load sensor is provided at a front part of one of the right and left side frames. A front end section of the one side frame more frontward than a shaft center of the rod of the load sensor includes a tapered-shape section. And an upper flange and a lower flange are formed at an upper edge and a lower edge of the tapered-shape section, respectively, the upper flange and the lower flange extending inward toward a center of the vehicle seat.

Abstract: A die body includes a die hole for punching a work. A core, including a discharge hole, which is in communication with the die hole, is provided in the die body. The core is provided with a plurality of fluid injection ports through which fluid is injected downward of the discharge hole. The die body is provided with inflow ports through which compressed fluid flows into the fluid injection ports. The core is made of resin. The discharge hole is tapered toward its upper side. An outer peripheral surface of the die body is provided with a peripheral groove which is in communication with the inflow ports.

Abstract: A vehicle seat includes a load sensor that is configured to measure a load applied from an occupant, a seat cushion frame that includes a right side frame and a left side frame, and a pan frame. The load sensor is provided at the seat cushion frame. Front parts of the right and left side frames are covered with the pan frame from above, and the pan frame includes a downward extending section that is arranged more frontward than a shaft center of the rod of the load sensor and that is arranged, with respect to a center of the vehicle seat, outside of one of the right and left side frames.

Abstract: A vehicle seat includes a load sensor that is configured to measure a load applied from an occupant, a seat cushion frame that includes a right side frame and a left side frame, a pan frame, and a rail extending along a front-rear axis. An outside protruding section of one of the right and left side frames and a shaft center of the rod are intersected by a same vertical plane that is orthogonal to the rail.

Abstract: A vehicle seat includes a load sensor for measuring a load applied from an occupant and a seat cushion frame, wherein the seat cushion frame comprises right and left side frames extending in a front-and-rear direction, the load sensor is attached to the seat cushion frame, and a concave portion is formed in at least one of the right and left side frames at a position opposite to the load sensor.

Abstract: A vehicle seat includes a load sensor for measuring a load applied from an occupant and a seat cushion frame, wherein the seat cushion frame comprises right and left side frames extending in a front-and-rear direction, the load sensor is attached to the seat cushion frame, and a concave portion is formed in at least one of the right and left side frames at a position opposite to the load sensor.