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: In a cutting die having a cutting chip, applied to a punch press, and cutting a work in collaboration with a cutting punch, a resistance member for guiding swarf generated during cutting of the work through the cutting chip and dividing it by giving resistance to it is provided around a scrap discharge hole so that the divided swarf does not remain in the scrap discharge hole but is discharged to an outside so as to prevent clogging by scrap.

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 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: Disclosed is, as a high-strength steel plate of API X80 grade or higher with a thickness of 38 mm or more, a thick steel plate for structural pipes or tubes that exhibits high strength in the rolling direction and excellent Charpy properties at its mid-thickness part without addition of large amounts of alloying elements. The thick steel plate for structural pipes or tubes disclosed herein has: a specific chemical composition; a microstructure at its mid-thickness part that is a dual-phase microstructure of ferrite and bainite with an area fraction of the ferrite being less than 50%, and that contains ferrite grains with a grain size of 15 ?m or less in an area fraction of 80% or more with respect to the whole area of the ferrite; a tensile strength of 620 MPa or more; and a Charpy absorption energy vE?20+ C. at ?20° C. at the mid-thickness part of 100 J or more.

Abstract: High-strength steel having a specified chemical composition wherein the ratio of Ti to N, Ti/N, is 2.0 to 4.0, and X (%), as calculated by equation (1): X=0.35Cr+0.9Mo+12.5Nb+8V (1) is 0.90% or more, wherein the symbols of chemical elements in equation (1) respectively denote the contents (mass %) of the corresponding chemical elements and wherein the symbol of a chemical element which is not included is assigned a value of 0, a microstructure having a bainite phase fraction of 70% or more, and a tensile strength of 760 MPa or more at a temperature of 350°C., methods for manufacturing such high-strength steel, and methods for manufacturing steel pipe from such high-strength steel, is disclosed.

Abstract: A high-strength steel having a specified chemical composition, wherein parameter Peff is 0.050% or more, the relationship (TS0?TS)/TS0?0.050 is satisfied, wherein TS is defined as tensile strength determined at a temperature of 350° C. after aging has been performed under the condition of a Larson-Miller Parameter (LMP) of 15700, and wherein TS0 is defined as tensile strength determined at a temperature of 350° C. before the aging is performed, and having a toughness represented by a vE?20 of 100 J or more in a weld heat-affected zone, which is formed when welding is performed.

Abstract: Disclosed is, as a high-strength steel plate of API X100 grade or higher, a steel plate for structural pipes or tubes that exhibits high strength in a rolling direction and that has only a small difference between strength in a rolling direction and strength in a direction perpendicular to the rolling direction (exhibiting high material homogeneity) without addition of large amounts of alloying elements. The steel plate for structural pipes or tubes disclosed herein has: a specific chemical composition; a microstructure mainly composed of bainite and containing martensite austenite constituent in an area fraction of less than 3.0%; a tensile strength in the rolling direction of 760 MPa or more; and TSC?TSL being 30 MPa or less in terms of absolute value, where TSC denotes a tensile strength in a direction perpendicular to the rolling direction.

Abstract: Disclosed is, as a high-strength steel plate of API X80 grade or higher with a thickness of 38 mm or more, a thick steel plate for structural pipes or tubes that exhibits high strength in the rolling direction, excellent Charpy properties at its mid-thickness part, and high material homogeneity without addition of large amounts of alloying elements. The thick steel plate for structural pipes or tubes disclosed herein has: a specific chemical composition; a microstructure mainly composed of bainite; a tensile strength of 620 MPa or more; a Charpy absorption energy vE?20° C. at ?20° C. at the mid-thickness part of 100 J or more; a variation of Vickers hardness in a plate thickness direction ?HV10,t of 50 or less; and a variation of Vickers hardness in a plate widthwise direction ?HV10,c of 50 or less.

Abstract: High-strength steel having a specified chemical composition, wherein X (%) calculated by using equation (1): X=0.35Cr+0.9Mo+12.5Nb+8V??(1) is 0.75% or more, wherein the symbols of chemical elements in equation (1) respectively denote the contents (mass %) of the corresponding chemical elements and wherein the symbol of a chemical element which is not included is assigned a value of 0, a microstructure having a bainite phase fraction of 50% or more, a dislocation density of 1.0×1015/m2 or more after aging has been performed under the condition of a Larson-Miller parameter (LMP) of 15000, and a yield strength of 550 MPa or more before and after the aging is performed, as well as methods of manufacturing such high-strength steel, is disclosed. The high-strength steel can be used as a raw material for manufacturing large diameter steel pipe having the strength properties required for its use in steam transportation.

Abstract: A steel composition and method from making a dual phase steel therefrom. The dual phase steel may have carbon of about 0.05% by weight to about 0.12 wt %; niobium of about 0.005 wt % to about 0.03 wt %; titanium of about 0.005 wt % to about 0.02 wt %; nitrogen of about 0.001 wt % to about 0.01 wt %; silicon of about 0.01 wt % to about 0.5 wt %; manganese of about 0.5 wt % to about 2.0 wt %; and a total of molybdenum, chromium, vanadium and copper less than about 0.15 wt %. The steel may have a first phase consisting of ferrite and a second phase having one or more of carbide, pearlite, martensite, lower bainite, granular bainite, upper bainite, and degenerate upper bainite. A solute carbon content in the first phase may be about 0.01 wt % or less.

Abstract: A punch die is provided. The punch die includes a punch body, a punch guide configured to removably receive the punch body therein, a retainer collar detachably coupled to the punch guide, a punch head mated to the punch body to regulate a position of the punch body, and a spring interposed between the punch head and the retainer collar. The punch guide includes a peripheral slot defined on the internal periphery of the punch guide such that the peripheral slot intersects a keyway of the punch guide. The retainer collar includes a cylindrical projection that extends into the inner periphery of the punch guide and an engaging projection defined on an outer periphery of the cylindrical projection. The engaging projection is rotatable to engage the peripheral slot and to be releasably aligned with the keyway.

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 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: Provided is a railway vehicle wheel that enables further reducing wear and fatigue damage of the wheel and rail in total. A railway vehicle wheel containing, in mass %: 0.65% to 0.84% of C; 0.1% to 1.5% of Si; 0.05% to 1.5% of Mn; 0.025% or less of P; 0.015% or less of S; 0.001% to 0.08% of Al; and 0.05% to 1.5% of Cr, the balance being Fe and incidental impurities, wherein a microstructure at least in a region extending from a tread to a depth of 15 mm is a pearlite structure, and a pearlite lamellar spacing at least in the region is 150 nm or less.

Abstract: A weld joint with an excellent CTOD property is produced with a weld metal, using a steel plate as a base metal. The steel plate has a chemical composition including C: 0.03% to 0.09%, Si: 0.01% to 0.35%, Mn: 1.3% to 2.0%, P: 0.012% or less, S: 0.0035% or less, Al: 0.01% to 0.06%, Ni: less than 0.3%, Mo: less than 0.10%, Nb: 0.005% to 0.023%, Ti: 0.005% to 0.025%, B: less than 0.0003%, N: 0.002% to 0.005%, Ca: 0.0005% to 0.0050%, and O: 0.0030% or less, with the components additionally satisfying a predetermined relationship. The weld metal has a chemical composition including C: 0.040% to 0.090%, Si: 0.1% to 0.8%, Mn: 1.0% to 2.5%, Al: 0.020% or less, Ni: 0.1% to 1.0%, Mo: 0.05% to 0.50%, Ti: 0.005% to 0.050%, and B: 0.0015% or less, the balance being Fe and incidental impurities.

Abstract: A high-tensile-strength steel plate is provided with a new chemical composition design that guarantees the same properties as a 50 mm thick steel plate even in a steel plate with a thickness of 100 mm or greater, without the yield stress being affected by the plate thickness. By mass %, the chemical composition includes C: 0.02% to 0.08%, Si: 0.01% to 0.35%, Mn: 1.4% to 2.0%, P: 0.007% or less, S: 0.0035% or less, Al: 0.010% to 0.060%, Ni: 0.5% to 2.0%, Mo: 0.10% to 0.50%, Nb: 0.005% to 0.040%, Ti: 0.005% to 0.025%, B: less than 0.0003%, N: 0.002% to 0.005%, Ca: 0.0005% to 0.0050%, and O: 0.003% or less, with the components additionally satisfying a predetermined relationship.

Abstract: In a cutting die having a cutting chip, applied to a punch press, and cutting a work in collaboration with a cutting punch, a resistance member for guiding swarf generated during cutting of the work through the cutting chip and dividing it by giving resistance to it is provided around a scrap discharge hole so that the divided swarf does not remain in the scrap discharge hole but is discharged to an outside so as to prevent clogging by scrap.

Abstract: A high toughness and high tensile strength thick steel plate has a plate thickness of 100 mm or more, wherein a reduction of area in a center of the plate thickness by tension in a plate thickness direction is 40% or more. Thus, a high tensile strength thick steel plate with excellent strength and toughness in a center of the plate thickness can be obtained with no need for a larger production line, even in the case of producing a high strength thick steel plate for which the addition amount of alloying element needs to be increased.