Abstract: A hybrid welding method of laser welding and arc welding for a T-joint in which a rib as one member to be welded abuts orthogonally onto a surface of a flange as other member to be welded includes forming a groove portion on a lateral surface of the rib that is an abutting part between the rib and the flange forming the T-joint; forming a flat part at a bottom part of the groove portion formed in the abutting part between the rib and the flange; and performing a hybrid welding using both laser welding in which the groove portion A with this flat part therein is irradiated with a laser beam, and arc welding, to form weld beads of weld metal in the groove portion A, so that welding together the flange and the rib forming the T-joint.

Abstract: The present invention provides a method of manufacturing a core shroud for a nuclear plant and a nuclear power plant structure in which a groove portion is easily assembled in the case of manufacturing the core shroud having a weld structure of a nuclear power plant by a laser welding, and it is possible to obtain a weld joint portion in which a plastic distortion region and a residual stress are as small as possible, going with a solidification shrinkage of the weld portion. At a time of welding butted portions of a plurality of members constructing a core shroud, a root face is provided in the butted portion, a length of the root face is set to 25% to 95% of a thickness of the thinner one of the butted portions of a plurality of members, a narrow groove is provided in the other than the root face, and the butted portions are welded by a laser welding using a weld wire.

Abstract: The present invention provides a method of manufacturing a core shroud for a nuclear plant and a nuclear power plant structure in which a groove portion is easily assembled in the case of manufacturing the core shroud having a weld structure of a nuclear power plant by a laser welding, and it is possible to obtain a weld joint portion in which a plastic distortion region and a residual stress are as small as possible, going with a solidification shrinkage of the weld portion. At a time of welding butted portions of a plurality of members constructing a core shroud, a root face is provided in the butted portion, a length of the root face is set to 25% to 95% of a thickness of the thinner one of the butted portions of a plurality of members, a narrow groove is provided in the other than the root face, and the butted portions are welded by a laser welding using a weld wire.

Abstract: An upper plate is arranged on the top surface of a lower vertical plate to form a T-type joint, and a penetration promoter is applied on the surface of the upper plate of the T-type joint. Subsequently, when performing non-consumable electrode arc welding, a penetration width w of a molten pool on the side of the vertical plate after penetrating through the back side of the vertical plate is formed equal to or greater than the vertical plate thickness if a lower vertical plate thickness is the same thickness as an upper plate thickness or thinner than the upper plate thickness, and the penetration width of the molten pool is formed equal to or greater than the upper plate thickness if the lower vertical plate thickness is thicker than the upper plate thickness, thereby forming a penetration shape having a desired welding metal part.

Abstract: The present invention has an object to reduce residual stress in a tensile direction of a weld on the inner side in contact with reactor water of austenitic stainless steel piping, and to change the residual stress into compressive stress, to reduce stress corrosive cracking. The present invention provides a welding process for stainless steel piping of laminating two types of welding wire made of different materials in a groove of austenitic stainless steel piping, including at least one of a first layer penetration welding step of performing a predetermined back bead width on the back side of the groove bottom and a tack welding step, a first lamination welding step of lamination welding of austenitic stainless steel wire from the bottom to the top of the groove, and a second lamination welding step of lamination welding of nickel-base alloy wire to a final layer at the top of the groove.

Abstract: A magnetic domain controlling film for controlling the magnetic domain of a magnetoresistive film is formed by the patterning technique on a lower insulating film formed on a lower shield film. The magnetoresistive film is formed on the magnetic domain controlling film for converting a magnetic signal from a magnetic recording medium into an electrical signal using the magnetoresistive effect. A resist pattern is formed by the lift-off method on the magnetoresistive film in such a fashion as to leave a region of the magnetoresistive film corresponding to the tracks of the magnetic recording medium. A magnetoresistive element is formed by ion milling leaving only the portion of the magnetoresistive film corresponding to the tracks.

Abstract: A magnetic domain controlling film for controlling the magnetic domain of a magnetoresistive film is formed by a patterning technique on a lower insulating film formed on a lower shield film. The magnetoresistive film is formed on the magnetic domain controlling film for converting a magnetic signal from a magnetic recording medium into an electrical signal using the magnetoresistive effect. A resist pattern is formed by the lift-off method on the magnetoresistive film in such a fashion as to leave a region of the magnetoresistive film corresponding to the tracks of the magnetic recording medium. A magnetoresistive element is formed by ion milling leaving only the portion of the magnetoresistive film corresponding to the tracks.

Abstract: A thin film magnetic head comprising a sintered ceramic substrate, an underlayer, a bottom magnetic core film, a magnetic gap film, an insulating film containing coil windings, a top magnetic core film, and a protective layer. The substrate and other films and layers form an air bearing surface. The under layer, the magnetic gap film and the protective layer comprise Al.sub.2 O.sub.3, and the bottom and the top magnetic core films comprise Ni--Fe alloy. This structure gives substantially the same etching rate, when the air bearing surface is polished using a working fluid of pH 6-8, for any of the substrate, the films comprising Al.sub.2 O.sub.3 and metal oxide described above, and the films of Ni--Fe alloy. Thus, steps (pole top recessions) on the air bearing surface can be made as small as 0.015 .mu.m or less. Accordingly, the magnetic head can be held in a stable attitude, thus obtaining good recording characteristics.

Abstract: A magnetic disc apparatus is disclosed, in which a magneto-resistance effect film converts a magnetic signal into an electrical signal by use of the magneto-resistance effect, a pair of electrodes supplies a signal detection current to the magneto-resistance effect film, and a magnetic domain control layer controls the magnetic domain of the magneto-resistance effect film. The magneto-resistance effect film, the electrodes and the magnetic domain control layer constitute a magnetic head of magneto-resistance effect type. An isolation film is formed in a magneto-sensitive portion of the magneto-resistance effect film between the magneto-resistance effect film and the magnetic domain control layer to break the magnetic coupling between the magneto-resistance effect film and the magnetic domain control layer.

Abstract: A magnetoresistive head has a substrate (1) and, on the substrate, a magnetoresistive film (40) for converting a magnetic signal into an electric signal by using magnetoresistance effects and a pair of electrodes (60) for causing a signal detection current to flow through the magnetoresistive film. A pair of first domain wall suppressing layers (30) are arranged at opposite end portions of the magnetoresistive film, respectively, to apply a longitudinal magnetic bias to the magnetoresistive film. A second domain wall suppressing layer (45) is also provided for applying a longitudinal magnetic bias, which is weaker compared with the longitudinal magnetic bias applied by the first domain wall suppressing layers, to the magnetoresistive film (40).

Abstract: A method of fabricating a thin-film magnetic in which a mask pattern in etching a bottom pole is formed of first and second mask films in this order when viewed from the bottom pole, the first mask film is used for defining, by self-alignment, the length of that portion of the side edge of a top pole which is nearly perpendicular to a magnetic gap, the second mask film makes it possible to etch the bottom pole with high dimensional accuracy, a non-magnetic film is formed on the mask pattern having the bottom pole thereunder and the exposed region of a substrate, and the top pole is formed after the mask pattern has been exposed and removed.

Abstract: A magnetic disc apparatus includes a magnetic disc for recording information; a thin film magnetic head including a magnetic pole structure having an upper magnetic pole tip and a lower magnetic pole tip arranged to provide a magnetic gap at respective end portions thereof for writing and reading information in and from the magnetic disc; a device for rotating the magnetic disc; and a device for positioning the thin film magnetic head; the upper and lower magnetic pole tips having different contours at the respective end portions as viewed from a side confronting the magnetic disc wherein the difference (.DELTA.CW in .mu.m) in the width, along the magnetic gap, of the upper magnetic pole tip and the width, along the magnetic gap, of the lower magnetic pole tip satisfies the relation0<.DELTA.CW.ltoreq.5000/Trfor the magnetic disc having a track density Tr of 1800 or more tracks per inch.

Abstract: A method of forming a thin film pattern on a base having a step portion. This method comprises a first step of forming a thin film of given material on the base, a second step of forming a predetermined pattern of a first photoresist film on said thin film at one of a first portion including a lower part of the step portion and a second portion including an upper part of the step portion, a third step of forming a predetermined pattern of a second photoresist film on said thin film at the other of the first and second portions and a fourth step of applying ion-milling to said thin film of given material using masks said first and second photoresist film patterns formed on said thin film at the first and second portions.

Abstract: In a welding apparatus having a plurality of electrodes and adapted for carrying out welding operation on a workpiece by alternately supplying currents to the individual electrodes through switching elements, an apparatus and method of controlling the currents supplied to the electrodes, comprising selecting the values of the currents supplied to the individual electrodes depending on the material of the workpiece, and carrying out the welding operation on the workpiece by alternately supplying the currents of the selected values to the individual electrodes respectively through the switching elements. The method is featured by the fact that the ratio between the individual currents is selected under the condition that the sum of the values of all the currents is maintained at a predetermined value.

Abstract: Disclosed is a method and apparatus for automatically controlling arc welding, wherein pieces of optical information provided by at least two bands of different wavelengths of light radiated from a weld area being arc-welded under predetermined welding conditions are alternately picked up by an optical device to extract various weld factors representing the actual status of the weld area from these pieces of optical information, and the extracted weld factors representing the actual status of the weld area are compared with the desired values of the weld factors representing the desired status of the weld area to compute the error or errors of the welding conditions, so that the welding conditions can be corrected on the basis of the detected error or errors of the welding conditions, whereby the weld factors can be controlled to the desired values.