A method of manufacturing a stator coil for an electric rotating machine includes the steps of: (1) forming substantially planar electric wires each of which includes in-slot portions to be received in slots of a stator core and turn portions to be located outside the slots to connect adjacent pairs of the in-slot portions; (2) rolling each of the planar electric wires through plastic deformation into a spiral or circular-arc shape; and (3) assembling the rolled electric wires together to form the stator coil. Further, in the rolling step, each of the planar electric wires is rolled by deforming each of the turn portions of the electric wire while restricting movement of at least one of the in-slot portions of the electric wire which is located closer to a rolling start end of the electric wire than the turn portion is.

Apparatus and methods for filament crimping. In one embodiment, the apparatus comprises a body and a filament crimp element. The filament crimp element comprises a first set of cavities disposed at a spacing which creates a first set of features and a second set of cavities disposed at a spacing which creates a second set of features. The first and second set cavities are substantially opposite one another. The first set of features are adapted to be placed at least partially within the second set of cavities and the second set of features are adapted to be placed at least partially within the first set of cavities. Methods and apparatus for the manufacture of the device are also disclosed. In addition, methods for automated placement and manufacture of assemblies using the crimp elements are also disclosed.

Disclosed is a corrugated plastic composite spring for a vehicle suspension and an apparatus and method for manufacturing the same. The apparatus includes a corrugated extrusion part, a braiding part, and a pultrusion part. The corrugated extrusion part forms a preform having a hollow corrugated structure. The braiding part weaves a three-dimensional woven fabric on the preform. The pultrusion part impregnates the three-dimensional woven fabric with thermosetting resin.

A braided carbon nanotube thread includes at least three carbon nanotube filaments braided into a thread. The carbon nanotube filaments include a plurality of carbon nanotubes, each of the carbon nanotubes having a length L. The carbon nanotube filaments are braided such that the carbon nanotube thread has at least 8 intersections per the length L of each carbon nanotube. The carbon nanotube thread has a tensile strength greater than the tensile strength of the constituent carbon nanotube filaments.

A tubular fibrous architecture is disclosed. According to one aspect, the tubular fibrous architecture includes a closed tubular part in at least one of its ends or bottom. The closed tubular part includes an architecture in which a textile material, such as a thread, roving, ribbon or bundle of threads, is continuously output from the bottom. Each textile material that is output from the bottom is continuously wound about the tubular part. All of the textile materials at the junction between the bottom and the remainder of the tubular part are continuous and there is a continuous geometric transition between the bottom architecture and the architecture of the remainder of the tubular part such that the textile materials in the tubular part cross over. A method of making such a tubular fibrous architecture is also disclosed.

Vascular treatment and methods include a plurality of self-expanding bulbs and a hypotube including interspersed patterns of longitudinally spaced rows of kerfs. Joints between woven structures and hypotubes include solder. Woven structures include patterns of radiopaque filaments measureable under x-ray. Structures are heat treated to include at least shapes at different temperatures. A catheter includes a hypotube including interspersed patterns of longitudinally spaced rows of kerfs. Heat treating systems include a detachable flange. Laser cutting systems include a fluid flow system.

Vascular treatment and methods include a plurality of self-expanding bulbs and a hypotube including interspersed patterns of longitudinally spaced rows of kerfs. Joints between woven structures and hypotubes include solder. Woven structures include patterns of radiopaque filaments measurable under x-ray. Structures are heat treated to include at least shapes at different temperatures. A catheter includes a hypotube including interspersed patterns of longitudinally spaced rows of kerfs. Heat treating systems include a detachable flange. Laser cutting systems include a fluid flow system.

Vascular treatment and methods include a plurality of self-expanding bulbs and a hypotube including interspersed patterns of longitudinally spaced rows of kerfs. Joints between woven structures and hypotubes include solder. Woven structures include patterns of radiopaque filaments measureable under x-ray. Structures are heat treated to include at least shapes at different temperatures. A catheter includes a hypotube including interspersed patterns of longitudinally spaced rows of kerfs. Heat treating systems include a detachable flange. Laser cutting systems include a fluid flow system.

A method of fabricating a mechanical member for aircraft, including a plurality of operations of braiding and depositing layers of braided reinforcing fibers on a mandrel (11) by using braiding machine. Each operation comprises braiding a braided layer and depositing it by moving the mandrel (11) along a central axis of the braiding machine. Each of the various superposed braided layers comprises both longitudinal fibers (12, 12G) that are parallel to a main direction of the mandrel (11), and interlacing fibers that are inclined. At least one operation is configured to form and deposit a braided layer having, in at least one cross-section of the member, a density of longitudinal fibers that differs depending on whether consideration is given to one angular region (S1) or another angular region (S2) of the same extent around the center of gravity (G) of the mandrel (11) in the section under consideration.

Vascular treatment and methods include a plurality of self-expanding bulbs and a hypotube including interspersed patterns of longitudinally spaced rows of kerfs. Joints between woven structures and hypotubes include solder. Woven structures include patterns of radiopaque filaments measurable under x-ray. Structures are heat treated to include at least shapes at different temperatures. A catheter includes a hypotube including interspersed patterns of longitudinally spaced rows of kerfs. Heat treating systems include a detachable flange. Laser cutting systems include a fluid flow system.

Vascular treatment and methods include a plurality of self-expanding bulbs and a hypotube including interspersed patterns of longitudinally spaced rows of kerfs. Joints between woven structures and hypotubes include solder. Woven structures include patterns of radiopaque filaments measureable under x-ray. Structures are heat treated to include at least shapes at different temperatures. A catheter includes a hypotube including interspersed patterns of longitudinally spaced rows of kerfs. Heat treating systems include a detachable flange. Laser cutting systems include a fluid flow system.

The protective sleeve for a motor component of the present invention is obtained by braiding multifilament yarns made of synthetic fibers into a cylindrical braided cord of at least 24 strands. The multifilament yarns have a single-yarn fineness of at least 15 dtex but less than 30 dtex and the yarn total fineness of a single braid unit of the braided cord is in the range of 800 to 1500 dtex. This protective sleeve has good covering properties and few voids. Therefore, a protective sleeve for a motor component is provided that has high partial discharge characteristics (electrical insulation performance) and good electrical insulation properties even when a step of washing away the raw yarn oil solution applied to the filaments was omitted.

An exhaust connection coupler and a method for manufacturing a braid cover incorporated therein are provided. The method of manufacturing comprises the steps of providing a tubular sleeve formed of braided wire filaments and forming at least one end of the sleeve into shape using a forming die such that the at least one end of the cover includes a circumferential neck portion having a diameter smaller than the diameter of a body portion of the cover. In the method, the sleeve may be pressed between male and female forming dies in order to create the cover's desired shape, which can include a shoulder extending radially outwardly from the cover's neck portion and meeting the cover's body portion at a corner.

A method of manufacturing a corrugated preform that allows a fiber volume fraction and an orientation angle to be substantially the same at a concave portion and at a convex portion when the corrugated preform is manufactured based on a braiding process. The method includes braiding a composite material corresponding to an outer diameter of a cylindrical cylinder shape, braiding the composite material by connecting a plurality of separate composite materials to one side of the braided composite material, and braiding the composite material to one side of the separate composite material corresponding to the outer diameter of the cylindrical cylinder shape.

A modular mold system for manufacturing a shell part of an oblong composite structure having a longitudinal direction from a fiber reinforced matrix material. The modular mould system includes a number of mold sections, which are adapted to being assembled to an assembled mold part. The number of mold sections includes a first mold section having a first molding surface with a contour that defines a surface of a first longitudinal part of the shell part and a first end section; and a second mold section having a second molding surface with a contour that defines a surface of a second longitudinal part of the shell part and a second end section; which, when the modular mold system is assembled to the assembled mold, the second end section of the second mold section abuts the first end section of the first mold section.

A system for accelerated manufacturing of concrete modular housing units including a first deck platform including a plurality of exterior movable wall forms. A second deck platform including a plurality of exterior movable wall forms. A first concrete slab is placed on the first deck platform. At least one core including a plurality of core walls placed on the first concrete slab. The exterior movable wall forms of the first deck platform are positioned proximate the core walls to define a wall space there between configured to receive wet concrete and create a first concrete modular housing unit. A second concrete slab is placed on the second deck platform. Wet concrete in the wall space is allowed to set a until it is partially cured and then the at least one core is removed from the first concrete slab and placed on the second concrete slab such that the at least one core can be reused one or more times during a predetermined amount of time to create a least a second concrete modular housing unit while the first concrete modular housing unit is still curing.

The organic light emitting display device includes an organic light emitting display panel and a data driver, wherein the organic light emitting display panel includes an active region which includes pixel driving TFTs for embodying an image and organic luminescent elements respectively connected with the pixel driving TFTs to emit light, a GIP region which includes a gate driver formed with a plurality of gate driving TFTs for respectively driving gate lines of the active region, a GND region formed between the GIP region and the active region to be formed with a base voltage line for supplying base voltage to the organic luminescent elements of the active region, and a sealant region formed with a sealant for attaching an upper substrate to a lower substrate, and wherein the GND region includes out-gassing blocking holes.

An electron emission element (1) includes an electrode substrate (2) and a thin film electrode (3), and emits electrons from the thin film electrode (3) by voltage application across the electrode substrate (2) and the thin film electrode (3). An electron accelerating layer (4) containing at least insulating fine particles (5) is provided between the electrode substrate (2) and the thin film electrode (3). The electrode substrate (2) has a convexoconcave surface. The thin film electrode (3) has openings (6) above convex parts of the electrode substrate (2).

A method of manufacturing a flexible display device includes: forming a soft substrate on a carrier substrate; forming a thin film layer comprising a display region on the soft substrate; removing a thin film layer excess portion of the thin film layer beyond an edge of the soft substrate; and separating the soft substrate and the carrier substrate.

An organic light emitting display resulting in an improved aperture ratio and a manufacturing method thereof. The organic light emitting display that includes a plurality of pixels arranged between first and second substrates, each of said pixels includes a plurality of thin film transistors, an organic light emitting diode, and a capacitor. The thin film transistors and the organic light emitting diode are formed on the first substrate and the capacitor is formed on the second substrate, and the thin film transistors and the capacitor are electrically connected with each other upon the first substrate being bonded to the second substrate.

A wiring board includes a first multilayer wiring board having first conductive layers and having a surface, a second multilayer wiring board having second conductive layers and positioned such that the second multilayer wiring board has a surface facing the surface of the first multilayer wiring board, and an adhesive layer including an adhesive sheet and interposed between the first multilayer wiring board and the second multilayer wiring board such that the adhesive layer is adhering the first multilayer wiring board and the second multilayer wiring board. The first multilayer wiring board has a first pad on the surface of the first multilayer wiring board, the second multilayer wiring board has a second pad on the surface of the second multilayer wiring board, and the first pad and the second pad are positioned such that the first pad and the second pad face each other across the adhesive layer.

The organic electroluminescence display device has a laminated portion on a base substrate. The device may have a cavernous portion formed by exploding a part of the laminated portion in a screening processing. A protective layer is formed to cover a whole surface of a wall defining the cavernous portion. Therefore, substances contained in the air are prevented from contacting to an organic electroluminescence layer at least partially defining the cavernous portion. Therefore, even if moisture is contained in the air, it is possible to prevent moisture from being absorbed by the organic electroluminescence layer. Moreover, since moisture is not absorbed by the organic electroluminescence layer, it is possible to reduce irregular spot on the device. In addition, it is possible to reduce a short circuit at an open defective portion.

To form stabilized organic light-emitting medium layers using the relief printing method and to provide an organic EL element excellent in terms of pattern-forming accuracy, film thickness uniformity and light-emitting characteristics, a substrate 2, first electrode layers 3 provided on the substrate 2, organic light-emitting medium layers 5 which are provided on the first electrode layers 3 and emit light when electrically connected, and second electrodes 6 which are provided on the organic light-emitting medium layers 5 and make the organic light-emitting medium layers 5 electrically connected when voltage is applied between the first electrodes 3 and the second electrodes are provided. In addition, at least one of the organic light-emitting medium layers 5 is formed of a mixture containing a polymer material having a weight-average molecular weight in a range of 1.5 million to 25 million and at least one low molecular material having a non-repetitive structure. Also, the mixing ratio between the polymer material and the low molecular material is set in a range of 0.05:1 to 0.5:1 in terms of weight ratio.

In a spark plug, a center electrode includes a base member and a discharge chip that has a higher melting point than the base member. The base member and the discharge chip are joined to each other by both a weld and a diffusion layer. The weld is formed, by fusion welding, along an outer periphery of an interface between the base member and the discharge chip into an annular shape. The weld is made up of those parts of the base member and the discharge chip which are molten and mixed together during the fusion welding and solidified after the fusion welding. The diffusion layer is formed radially inside the annular weld. The diffusion layer is made up of those parts of the base member and the discharge chip which are diffused into each other across the interface between the base member and the discharge chip.

A method of manufacturing a display panel of an organic light emitting display device includes determining a plurality of pixel groups, the pixel groups corresponding to groups of pixels of the display panel, calculating aperture ratios for the pixels, respective aperture ratios being calculated by pixel group based on respective distances between a power unit and the pixel groups, and forming the pixels of the display panel to have the respective aperture ratios according to the corresponding pixel groups.

A method for manufacturing high speed pressure compensator-type drip irrigation tubes and the tubes obtained thereby having absolute radial orientation of molecular chains, the orientation imparting strength as well as flexibility to the tube material. The said method comprises extruding a tube using a plurality of extruders; blowing up the extruded tube by introducing a pressure inside the tube relatively higher than the pressure outside the tube; drawing the blown tube simultaneously to the blowing of tube; flattening the blown tube by heat welding the collapsed halves together and forming a tape immediately, subsequent to the process of blowing and drawing the tube; extrusion of a bonding polymer on one border of the tape; printing flow channels into the hot and viscous bonding polymer; and forming a tube by lengthwise folding the tape and heat welding the overlapping borders together using the bonding polymer.

A top cover for use in a disk drive apparatus includes a plate made of a metal and a gasket fixed to the plate. The gasket is made of an elastomer. A surface of the plate includes a fixing region to which the gasket is closely adhered. The fixing region includes a plurality of ridges and in plan view a plurality of filamentous projections extending from each of the plurality of ridges. The plurality of ridges are arranged in the fixing region to increase a surface area of the fixing region. The plurality of ridges and the plurality of filamentous projections extending from each ridge are distributed over the fixing region.

A spherical annular seal member 40 includes: a spherical annular base member 38 which is defined by a cylindrical inner surface 34 defining a through hole 33 in a central portion, a partially convex spherical surface 35, and annular end faces 36 and 37 on large- and small-diameter sides of the partially convex spherical surface 35; and an outer layer 39 formed integrally on the partially convex spherical surface 35 of the spherical annular base member 38.

A coating composition has a natural fiber-bearing dry matter mixture, as well as cellular plastic grains, mixed into water. By spreading this composition onto any base, particularly by spraying, and by hardening it, particularly through drying, the coating is formed from the coating composition, which coating provides extremely good acoustic properties. If a special fiber base plate based on chemical pulp is used as the base of the coating, the plate-like acoustic element is obtained.

Described embodiments relate to a method of manufacturing a sound absorption material. The method comprises: forming a low density fibrous web to act as porous bulk absorber, the fibrous web containing a proportion of bi-components fibers, each bi-component fiber having a core material and a sheath material around the core material; applying a thin facing later to the low density fibrous web, wherein the facing layer is adhesively compatible with the sheath material; heating the fibrous web to a temperature sufficient to soften the sheath material of at least some of the bi-component fibers; and pressing the facing layer and fibrous web together under low pressure such that at least part of the facing layer contacts the softened sheath material of at least some of the bi-component fibers to form an adhesive bond between the facing layer and the fibrous web.

The present invention relates to a cliché and a method for manufacturing the same, and the cliché according to the present invention comprises a cliché comprising: a groove pattern, wherein the groove pattern comprises a region composed of linear patterns which do not intersect with each other and the region composed of linear patterns is a square region comprising two or more lines of a linear pattern in the region and comprises a region in which the line width (W) and the depth (D) of the linear pattern and the ratio (R) of a region which does not comprise the linear pattern in the square region and the aperture line width (W0) of a mask pattern for forming a pattern, which corresponds to the linear pattern, satisfy specific relationship equation(s). The cliché according to the present invention may prevent the bottom touch phenomenon of ink transferred onto the cliché.

The invention provides an infrared-sensitive positive-working image forming material which provides excellent development latitude, image formability and image region strength, and in which decrease in development property is prevented even when a certain time has passed after pattern exposure until development treatment; an infrared-sensitive positive-working planographic printing plate precursor which is formed from the image forming material and has excellent image formability and image region printing durability; and a method for manufacturing a planographic printing plate using the planographic printing plate precursor. The image forming material includes; on a support, a lower layer containing a polymer having carboxylic acid groups at side chains thereof, at least a part of the carboxylic acid groups forming a salt structure with a monovalent basic compound, and an infrared absorbing agent; and an upper layer whose solubility to aqueous alkaline solution is increased by heat, in this order.

An array of hollow fibers including a plurality of hollow fibers of a predetermined diameter configured to receive a gas having oxygen therein and transfer the oxygen to a fluid and/or transfer carbon dioxide in the fluid to a gas. The array is configured in a predetermined pattern having a predetermined packing density that is a fraction of a total cross-sectional area of the array occupied by the hollow fibers.

A method of manufacturing coated paper by applying a coating liquid to a strip-shaped web of paper to form a plurality of bands extending in the width direction of the web and spaced from each other in the longitudinal direction of the web includes: a coating step (S1) of applying the coating liquid to the web to form the bands with a coating band pitch narrower than a design band pitch defined as a standard for the coated paper; an aftertreatment step (S2), executed after the coating step, of drying the web; and a tension applying step (S3), executed after the aftertreatment step, of expanding the band pitch of the web by applying tension to the web to cause the band pitch of the web to approach the design band pitch.

A method for manufacturing a sheet of paper and/or board having improved retention and drainage properties is provided, according to which, before the formation of the sheet and/or board, at least two retention aids are added to the fibrous suspension. These two retention aids are a main retention aid corresponding to a (co)polymer having a cationic charge density above 2 meq/g, obtained by the Hofmann degradation reaction, and a secondary retention aid corresponding to a water-soluble or water-swellable polymer having an anionic charge density above 0.1 meq/g. The main retention aid is introduced into the fibrous suspension in a proportion of 100 to 800 g/t of dry pulp, and the secondary retention aid is introduced into the fibrous suspension in a proportion of 50 to 800 g/t of dry pulp and has an intrinsic viscosity IV above 3 dl/g.

A sheet manufacturing apparatus includes a defibrating unit configured to defibrate a defibration object including at least a fiber, in air. The sheet manufacturing apparatus forms a sheet by adding quantity of heat to a defibrated material defibrated at the defibrating unit. The sheet manufacturing apparatus includes a measuring unit configured to acquire moisture amount information of the defibrated material or the defibration object, and a controller configured to control the quantity of heat to be added to the defibrated material on the basis of the moisture amount information.

A belt structure for a two-wheeled vehicle made by means of strip-like segments or elements, each including parallel cords embedded in an elastomeric layer, sequentially laid along the circumferential extension of a toroidal support so as to form a reinforcing layer having a continuous circumferential extension around a geometric rotation axis of the toroidal support, wherein each strip-like element is laid in a laying trajectory defining, at each point, a laying angle; at each point of the laying trajectory a laying gap is formed between adjacent strip-like elements; the laying trajectory is formed starting from preselected laying angles on the shoulder and on the crown of the tire; the laying gap between adjacent strip-like elements varies along at least one length of said laying trajectory between crown and shoulder so as to cause variation of the laying angle and obtain the preselected angles on the shoulder and on the crown.

In the invention, at least a tire outer circumferential side portion of a tread portion is formed of a non-conductive rubber layer. The non-conductive rubber layer is formed by winding and laminating a non-conductive rubber ribbon along a tire circumferential direction. A conductive layer is provided on an outer circumference of the non-conductive rubber ribbon, and the conductive layer continuously and spirally extends along the tire circumferential direction, and is exposed on a tread surface from a bottom surface of the non-conductive rubber layer toward a tire outer circumferential side. Accordingly, an electricity generated in a vehicle body is discharged to a road through the conductive layer. Since the conductive layer is scattered within the non-conductive rubber layer and exposure on the tread surface is preferably secured, it is possible to achieve an excellent conductivity.

A three component bullet with an improved core retention feature and a method of manufacturing the bullet is described including a cylindrical jacket having an open end and a closed end containing a malleable metal core which is forced into a forming die having a bottleneck shaped interior resulting in a bottleneck shaped pre-form wherein the outside diameter of the open-ended forward portion of the jacket is smaller than the outside diameter of its closed rearward portion. The open end of the pre-form may be dropped through or forced through a malleable locking band of appropriate height, diameter and wall thickness. A relatively tight-fitting punch enters the open end of the pre-form generating sufficient axial force against the face of the metal core to radially swell the core and subsequently portions of the jacket fore and aft of the locking band, thereby securing the locking band in place while at the same time producing an inwardly-extending annular band of jacket material which embeds itself into the core material with the result that the core is permanently locked inside the jacket.

Firearm projectiles and methods of manufacturing firearm projectiles from a supply of clad wire. In some embodiments, the clad wire is manufactured as electrical wire, such as copper-clad steel wire. Bullets and shot, as well as methods of forming bullets and shot, from clad wire are disclosed.

Penetrators and methods of manufacturing penetrators are disclosed. One method of manufacturing a penetrator having arrowhead geometry and base geometry includes the steps: (a) cold heading a piece of material to form a blank; (b) machining the blank to create the arrowhead geometry; and (c) roll forming the blank to create the base geometry. Another method of manufacturing a penetrator having arrowhead geometry and base geometry includes the steps: (a) machining a piece of material to create the arrowhead geometry; and (b) roll forming the piece of material to create the base geometry. Yet another method of manufacturing a penetrator from a blank includes the steps: (a) machining the blank to create a first surface feature of the penetrator; and (b) roll forming the blank to create a second surface feature of the penetrator.

A method for providing permanently colored steel shot for shot shells through anodizing and shells manufactured utilizing the shot.

Firearm projectiles and methods of manufacturing firearm projectiles from a supply of clad wire. In some embodiments, the clad wire is manufactured as electrical wire, such as copper-clad steel wire. Bullets and shot, as well as methods of forming bullets and shot, from clad wire are disclosed.

Metal nanoparticles having improved migration resistance are provided. The present invention relates to a method for manufacturing composite nanoparticles including obtaining composite nanoparticles containing at least silver and copper in a single particle by heat treating a mixture containing an organic silver compound and an organic copper compound at a temperature of 150° C. or more in a non-oxidative atmosphere in the presence of a tertiary amine compound represented by the general formula R1R2R3N (wherein R1 through R3 are optionally substituted alkyl groups or aryl groups that may be the same or different, R1 through R3 may be linked in a ring, and the number of carbon atoms in each of R1 through R3 is 5 through 18 and may be the same or different).

There is provided a sliding part in which a surface coverage ratio of copper in the sliding part increases. A bearing which is the sliding part is formed by filling the raw powder into the filling portion of the forming mold, compacting the raw powder to form a powder compact, which is sintered. A copper-based raw powder is composed of a copper-based flat raw powder whose diameter is smaller than that of an iron-based raw powder and an aspect ratio larger than that of the iron-based raw powder, and a copper-based small-sized raw powder whose diameter is smaller than that of the copper-based flat raw powder. The copper is allowed to segregate at the surface of the sliding part. The surface of the bearing is covered with the copper-based small-sized raw powder and the copper-based flat raw powder, thereby the surface coverage ratio of copper can be increased.

A process for manufacturing high aspect ratio silver nanowires is provided, wherein the recovered silver nanowires exhibit an average diameter of 25 to 80 nm and an average length of 10 to 100 μm; and, wherein the total glycol concentration is

[Object] To provide a method of manufacturing a sputtering target and a sputtering target that are capable of achieving refinement and uniformity of crystal grains. [Solving Means] A method of manufacturing a sputtering target according to an embodiment of the present invention includes forging an ingot formed of metal by applying a stress in a first axis direction (z-axis direction) and a plane direction (xy-plane direction) orthogonal to the first axis direction. The ingot is additionally forged by applying a stress in a second axis direction (axial directions c11, c12, c21, c22) obliquely intersecting with a direction parallel to the first axis direction. The ingot is heat-treated at a temperature equal to or higher than a recrystallization temperature thereof. In such a manner, since slip deformation can be caused not only in the first axis direction and the plane direction orthogonal thereto but also in the second axis direction, the high density and uniformity of an internal stress can be achieved.

A method of manufacturing a high-strength galvanized steel sheet includes hot-rolling a slab to form a steel sheet; during continuous annealing, heating the steel sheet to a temperature of 750° C. to 900° C. at an average heating rate of at least 10° C./s at a temperature of 500° C. to an A1 transformation point; holding that temperature for at least 10 seconds; cooling the steel sheet from 750° C. to a temperature of (Ms point—100° C.) to (Ms point—200° C.) at an average cooling rate of at least 10° C./s; reheating the steel sheet to a temperature of 350° C. to 600° C.; holding that temperature for 10 to 600 seconds; and galvanizing the steel sheet.

A manufacturing method for a composite steel part including manufacturing a first steel part by preparing an intermediate product in which an extra portion is added, and heating the intermediate product to an austenitizing temperature in a carburizing atmosphere to form a carburized layer, cooling the intermediate product at a rate less than a cooling rate at which martensitic transformation is caused and in which the intermediate product is cooled to a temperature equal to or less than a temperature at which structure transformation due to the cooling is completed, heating the intermediate product to an austenitizing range by high-density energy and thereafter cooled at a rate equal to or more than the cooling rate at which martensitic transformation is caused to form a carburized quenched portion, cutting the extra portion of the intermediate product, and welding the first steel part and the second steel part to each other.

A method for manufacturing a hot-rolled sheet attains grain refinement of the steel sheet whose grain size is extremely fine. In particular, a ferrite grain size of less than average 2 μm is obtained, which is not laminar but has ferrite grains with equiaxed morphology and exhibits high formability in forming. The method comprises the steps of rolling and cooling, wherein the rolling reductions, cooling steps, and temperature are closely regulated. A hot rolled sheet made from the method of manufacturing has a controlled ferrite grain in different regions of sheet thickness.