Abstract: A powder magnetic core mainly comprises a soft magnetic powder which contains: 0.5 to 15% by mass of Si; 10% by mass or less of Al; and the balance of Fe and unavoidable impurities. The powder has an apparent density/true density falling within in a range of 0.4 to 0.55, and a volume percentage of the soft magnetic powder is 80% by volume or more. An initial permeability of the core at 100 kHz is 125 or more.

Abstract: The multi-layered heat resistant metal tube is disclosed. This tube has excellent anti-coking characteristics and is suitable for use under the conditions where carbon tends to deposit and accumulate thereon due to contacting with hydrocarbons at a high temperature. The tube is made by forming weld-mounted overlaid layer of Cr—Ni alloy by building-up welding over the inner surface and/or the outer surface of a substrate tube made of a heat resistant metal. The Cr—Ni alloy comprises 35% by weight or more of Cr and satisfies the relationship: Ni(w%)≧0.5Cr(wt %). Building-up welding is preferably carried out by PPW (Plasma Powder Welding) in which the filler metal is supplied in the form of powder.

Abstract: A Ti-base wire rod for forming molten metal excellent both in rod Seeding smoothness and arc stability is disclosed. A wire rod 301 is composed of Ti metal, and has in the surficial portion including the surface thereof an oxygen enriched layer having an oxygen concentration higher than that in an inner portion. Ratio Tw/Dw of the thickness Tw of the oxygen enriched layer and the diameter Dw of the wire rod is adjusted within a range from 1×10−3 to 1×10−1, and the average oxygen concentration of the oxygen enriched layer is adjusted to 1 wt % or above.

Abstract: A semiconductor surface-emitting element having a light-emitting portion and formed of a plurality of semiconductor layers including a plurality of light-generating layers of a quantum well structure for generating lights having respective different emission spectra whose peak wavelengths are different from one another, and a light resonator consisting of a pair of reflecting layers between which the light-generating layers are interposed for reflecting the lights generated by the light-generating layers, so that a light resonated by the light resonator is emitted from the light-emitting portion.

Abstract: A melting apparatus having a compact structure, of economical equipment cost, enabling to vacuum melting and refining at high productivity. A metal melting apparatus has a structure in which a refractory furnace wall 12 is furnished on an outer circumference thereof with a seal jacket 16 of air tight and non-electrical conductivity, and disposed with vertical water cooling copper pipes 47 along the inner circumference of the seal jacket 16 at predetermined space, and the furnace casing 10 is arranged at the outer part to encircle the furnace casing with an induction heating coil 38, and the furnace casing 10 is secured to a frame 42 by means of the seal jacket 16 for reinforcing the structure. The seal jacket 16 of the furnace casing 10 is fixed to the frame via an upper flange 44 and a lower flange 28.

Abstract: Gas shielded arc welding is performed using gas nozzle 10 which includes a straight portion 14 that permits the shielding gas flows from orifices 18 to flow parallel to the axial direction and a constricted portion 20 continuous from the straight portion 14 that constricts the gas flows from the straight portion 14 as they travel toward the distal end and the nozzle 10 satisfies the following relations (1) and (2): 1.5≦(Dp/Do)≦2.5  (1) 1.0≦(L/Dp)  (2) where Dp is the inside diameter of the straight portion 14, Do is the inside diameter of the distal gas outlet of the constricted portion 20, and L is the axial length of the constricted portion 20.

Abstract: There is disclosed a powder magnetic core in which a permeability does not easily drop even when an applied magnetic field intensifies, comprising: a bulk body containing a main component of a powder of an Fe-base alloy having a soft magnetic property, and the balance substantially including a heat-treated insulation binder and a void.

Abstract: A contact provided in a welding tip of an arc welding apparatus includes a tip body adapted to be mounted to a welding torch body and a tip end member formed integrally therewith. The tip end member is divided into two parts, i.e., first and second halves by means of a slit formed along the axis of the tip end member, and the first half having the predetermined rigidity is movable around a connection between itself and the tip body. A spring member fitted on the tip end member applies a spring force thereto, whereby the contact has improved durability.

Abstract: A head slider for a flexible magnetic disk has a magnetic pole pad including a magnetic head buried in the pad and being disposed on a surface of the head slider opposed to the flexible magnetic disk, and the magnetic head performs the recording of a signal on the flexible magnetic disk or the reproducing of the signal from the flexible magnetic disk in a state that the pad contacts the flexible magnetic disk rotating at a relative speed of 0 m/s to 25.0 m/s to the magnetic head.

Abstract: A molten steel of a special steel or the like including a high-alloy steel is poured in a mold whose bottom portion is closed with a dummy head of a lift table. As the lift table is vertically moved down at a given casting speed, a casting whose lower end is supported by the dummy head is continuously pulled out from the bottom portion of the mold. As a pair of movable molds that constitute the mold are relatively moved away from each other in synchronism with the downward movement of the lift table, both widthwise side surfaces of the casting are provided with required tapering.

Abstract: A steel for shaft, which has corrosion resistance, machinability, and straightness at substantially the same levels as those of free cutting steel 12L14 plated with Ni, which has conventionally been used as a steel for shaft, and need not be plated on its surfaces, thus making it possible to reduce the production cost therefor, and which comprises: 0.05% by mass or less of C; 0.15% by mass or less of Si; 0.40% by mass or less of Mn; 6.0 to 10.0% by mass of Cr; 0.10% by mass or less of S; 0.30 to 0.80% by mass of Ni; 0.10 to 0.30% by mass of Pb; 0.001 to 0.10% by mass of N; and the balance of Fe and an unavoidable impurity; and a steel shaft composed of said steel.

Abstract: A magnetic mixture comprising at least two kinds of powders which are uniformly mixed with each other. Each powder exhibits a significant magnetic property when its constituent elements have a predetermined composition ratio. Magnetic properties of each powder are retained in the magnetic mixture which exhibits, as a whole, a soft magnetic property. The magnetic mixture is useful as a raw material for a powder magnetic core.

Abstract: A powder magnetic core is made from powder containing Fe-based soft magnetic powder as a major component. Provided that an initial permeability of the core is &mgr;0 and that a permeability of the core observed when a magnetic field of 24 kA/m is applied to the core is &mgr;, &mgr;0 and &mgr; fulfill the relationship &mgr;/&mgr;0≧0.5. Specifically, the powder magnetic core is made from 60 to 75 volume % of soft magnetic powder having an aspect ratio (L2/L1) of 1 to 1.5 and the balance containing an insulating binder as a major component, and the content of the insulating binder is 5 to 20 parts by weight with respect to 100 parts by weight of the soft magnetic powder. The powder magnetic core shows a small reduction in the permeability even when the strength of a magnetic field applied thereto is increased.

Abstract: A metal pipe inner surface weld-mounting apparatus having a monitoring device is constituted by an arm, a horizontal torch, a mirror, a camera and a monitoring device. The arm has a supported base end portion, which is horizontally extended. The horizontal torch is attached to a leading end portion of the arm. The weld-mounting is performed on an inner surface portion of a metal pipe supported rotatably around a horizontally extending axis while at least one of the metal pipe and the horizontal torch is moved in a direction of the axis. The mirror is attached to the leading end portion of the arm. The camera is disposed in a position separated from the mirror for picking up an image of weld-mounting beads in a neighborhood of arc light of the horizontal torch through the mirror. The monitoring device monitors a condition of the weld-mounting.

Abstract: The present invention provides a metal pipe bonded body formed from a plurality of metal pipes. Each metal-pipe is formed with an elongated, pre-formed portion at each end, and a central portion, each elongated, preformed portion having a constant inside diameter greater than an inside diameter of the central portion of each metal pipe.

Abstract: A quantum well type light-emitting diode having a light-emitting portion and formed of a plurality of semiconductor layers including at least one light-generating layer of a quantum well structure for generating a light, and a pair of reflecting layers between which the at least one light-generating layer is interposed for reflecting the light generated by the at least one light-generating layer, so that the pair of reflecting layers functions as a light resonator, the quantum well type light-emitting diode emitting the light generated by the light-generating layer from the light-emitting portion, wherein the improvement comprises: each of the at least one light-generating layer having a lattice constant which is smaller than that of at least two semiconductor layers of the plurality of semiconductor layers, which two semiconductor layers are located adjacent to and on opposite sides of the at least one light-generating layer.

Abstract: Carbon steel pipes are joined to each other in a non-oxidizing atmosphere by using an insert constituted by a Ni-base alloy or a Fe-base alloy having a melting point which is lower than 1200° C. and a thickness of 80 mm or smaller under conditions that the surface roughness Rmax of the joined surfaces of the carbon steel pipes is 20 &mgr;m or smaller, the joining temperature is not lower than 1250° C. nor higher than 1330° C., duration at the joining temperature is 30 seconds or longer and the pressure is not lower than 2 MPa nor higher than 4 MPa. The expanding operation is performed such that the maximum difference in level of the joined portion is not larger than 25% of the carbon steel pipe and the expansion ratio is 25% or lower.

Abstract: A powder magnetic core is made from powder containing Fe-based soft magnetic powder as a major component. Provided that an initial permeability of the core is &mgr;0 and that a permeability of the core observed when a magnetic field of 24 kA/m is applied to the core is &mgr;, &mgr;0 and &mgr; fulfill the relationship &mgr;/&mgr;0 0.5. Specifically, the powder magnetic core is made from 60 to 75 volume % of soft magnetic powder having an aspect ratio (L2/L2) of 1 to 1.5 and the balance containing an insulating binder as a major component, and the content of the insulating binder is 5 to 20 parts by weight with respect to 100 parts by weight of the soft magnetic powder. The powder magnetic core shows a small reduction in the permeability even when the strength of a magnetic field applied thereto is increased.

Abstract: A pair of rolling machines are arranged in series in alignment with a pass line along which a workpiece to be rolled is passed. The center distance between the first rolls of the first rolling machine and second rolls of the second rolling machine is designed to be not more than 1.5 times the roll diameter. The rotational axes of the first rolls are displaced by an angle of 90° from those of the second rolls and are inclined at an angle of 45° respectively with respect to the horizontal plane. A plurality of dual-purpose calibers are defined between the rolls of the rolling machines to be arranged in the axial direction, respectively. The rolls are shifted in crossing directions to the pass line respectively so as to bring desired dual-purpose calibers in alignment with the pass line.

Abstract: A granulated powder for a high-density sintered body is provided, which has an excellent flow rate and an excellent sintered density, and a sintered body produced using the same is provided. The granulated powder is obtained by granulation using a binder and a powder material comprising small diameter particles comprised of stainless steel and having an average particle diameter of 1 to 20 &mgr;m and large diameter particles comprised of stainless steel and having an average particle diameter of 30 to 150 &mgr;m. The content of the small diameter particles in the granulated powder is 30 to 70% by weight, and at least part of the small diameter particles adheres to the surfaces of the large diameter particles to form skin particles.