Abstract: A welding wire is formed from a hoop having an inner surface and formed from a metal material, a core wire having a surface and formed from a metal material, and an alkaline metal compound. The hoop metal material and the core wire metal material are different from each other. A composition of the welding wire is divided into the hoop metal material and the core wire metal material. The alkaline metal compound is disposed between the inner face of the hoop and the surface of the core wire. An amount of the alkaline metal compound is from more than 10 ppm to 1000 ppm based on a weight of the welding wire.

Abstract: Provided are a welding method and a weld joint with which the fatigue strength of the box-welded joint of a gusset plate and a high-tensile steel can be dramatically improved. A welding method whereby a gusset plate is welded to high-tensile steel by means of box-welding, with a bead having a length of 17 mm or greater being formed at the ends of the gusset plate in the lengthwise direction using a welding material for which the martensite transformation starting temperature of the weld metal is 350° C. or less. In addition, a weld joint formed by welding a gusset plate to high-tensile steel using the aforementioned method; a method for repairing or reinforcing a box-welded part.

Abstract: The invention is a welding method capable of controlling an arc heat distribution on a groove face of a base metal, which comprises increasing or decreasing the melting rate of a welding wire relative to the feeding rate of the welding wire by changing the characteristic of an arc current to thereby change an arc generating position of a fusing end of the welding wire, wherein an AC arc welding operation is performed by changing the polarity of the welding wire as the characteristic of the arc current; and a welded joint structure formed by the welding method.

Abstract: The invention is a welding method capable of controlling an arc heat distribution on a groove face of a base metal, which comprises increasing or decreasing the melting rate of a welding wire relative to the feeding rate of the welding wire by changing the characteristic of an arc current to thereby change an arc generating position of a fusing end of the welding wire, wherein an AC arc welding operation is performed by changing the polarity of the welding wire as the characteristic of the arc current; and a welded joint structure formed by the welding method.

Abstract: The invention provides a welding system capable of freely controlling the dispersion and concentration of arc heat over the groove face with an extreamly narrow gap and a high strength and high quality welded joint structure which is formed by this welding system and which is capable of preventing softening/hardening of the structure, the lowering of the toughness thereof and the generation of a crack. According to the welding system, the melting rate of a welding wire is controlled relative to the welding wire feeding rate by changing the characteristic of an arc current so that the range of behavior and the transfer rate of the arc pole (the arc generating main point at a groove surface) are controlled. Further, the welded joint structure consists of a high strength steel having a superfine grain structure with a carbon equivalent of as low as less than 0.

Abstract: A method of consumable electrode type gas shield arc welding characterized in that a shield gas consisting of an inert gas is fed toward a consumable electrode and an addition gas consisting of a mixture of oxidizing gas and inert gas toward an outer edge of welding pool. Further, there is provided a welding torch for use in the method. Thus, in the welding of steel material in accordance with GMA welding technique, the dissolved oxygen concentration of the weld metal can be reduced to 100 ppm or less, and while maintaining arc stability, desirable bead formation can be attained.

Abstract: A plurality of metal materials to be a composition, without containing a flux, of a required welded portion are laminated in order to improve characteristics such as toughness of the welded portion and to carry out a stable welding operation. A welding wire enclosing an alkaline metal compound is used between the layers. The welding is carried out in a high-purity inert gas atmosphere.

Abstract: The invention provides a welding system capable of freely controlling the dispersion and concentration of arc heat over the groove face with an extremely narrow gap and a high strength and high quality welded joint structure which is formed by this welding system and which is capable of preventing softening/hardening of the structure, the lowering of the toughness thereof and the generation of a crack. According to the welding system, the melting rate of a welding wire is controlled relative to the welding wire feeding rate by changing the characteristic of an arc current so that the range of behavior and the transfer rate of the arc pole (the arc generating main point at a groove surface) are controlled. Further, the welded joint structure consists of a high strength steel having a superfine grain structure with a carbon equivalent of as low as less than 0.

Abstract: In the present invention, an iron based alloy which contains by mass %: 0.20% or less of C; 6.0 to 16.0% of Cr; 6.0 to 16.0% of Ni and whose martensitic transformation starting temperature (Ms point temperature) is in the range of 0-170° C., inclusive of 0° C. and exclusive of 170° C., is used as a welding material. With respect to a weld metal, the weld metal has a iron alloy composition which contains by mass %: 0.20% or less of C; 3.0 to 13.0% of Cr; 3.0 to 13.0% of Ni and whose martensitic transformation starting temperature (Ms point temperature) is in the range of 50-360° C., inclusive of both 50° C. and 360° C.

Abstract: The invention provides a welding system capable of freely controlling the dispersion and concentration of arc heat over the groove face with an extreamly narrow gap and a high strength and high quality welded joint structure which is formed by this welding system and which is capable of preventing softening/hardening of the structure, the lowering of the toughness thereof and the generation of a crack. According to the welding system, the melting rate of a welding wire is controlled relative to the welding wire feeding rate by changing the characteristic of an arc current so that the range of behavior and the transfer rate of the arc pole (the arc generating main point at a groove surface) are controlled. Further, the welded joint structure consists of a high strength steel having a superfine grain structure with a carbon equivalent of as low as less than 0.

Abstract: In the present invention, an iron based alloy which contains by mass %: 0.20% or less of C; 6.0 to 16.0% of Cr; 6.0 to 16.0% of Ni and whose martensitic transformation starting temperature (Ms point temperature) is in the range of 0-170° C., inclusive of 0°C and exclusive of 170° C., is used as a welding material. With respect to a weld metal, the weld metal has a iron alloy composition which contains by mass %: 0.20% or less of C; 3.0 to 13.0% of Cr; 3.0 to 13.0% of Ni and whose martensitic transformation starting temperature (Ms point temperature) is in the range of 50-360° C., inclusive of both 50° C. and 360° C.

Abstract: The invention provides a welding system capable of freely controlling the dispersion and concentration of arc heat over the groove face with an extreamly narrow gap and a high strength and high quality welded joint structure which is formed by this welding system and which is capable of preventing softening/hardening of the structure, the lowering of the toughness thereof and the generation of a crack. According to the welding system, the melting rate of a welding wire is controlled relative to the welding wire feeding rate by changing the characteristic of an arc current so that the range of behavior and the transfer rate of the arc pole (the arc generating main point at a groove surface) are controlled. Further, the welded joint structure consists of a high strength steel having a superfine grain structure with a carbon equivalent of as low as less than 0.

Abstract: The invention provides a welding system capable of freely controlling the dispersion and concentration of arc heat over the groove face with an extreamly narrow gap and a high strength and high quality welded joint structure which is formed by this welding system and which is capable of preventing softening/hardening of the structure, the lowering of the toughness thereof and the generation of a crack. According to the welding system, the melting rate of a welding wire is controlled relative to the welding wire feeding rate by changing the characteristic of an arc current so that the range of behavior and the transfer rate of the arc pole (the arc generating main point at a groove surface) are controlled. Further, the welded joint structure consists of a high strength steel having a superfine grain structure with a carbon equivalent of as low as less than 0.

Abstract: A gas having an arc current-voltage property that is different from a shielding gas is intermittently added to the shielding gas, an arc current is intermittently changed in proportion to an intermittent chemical composition change of the shielding gas at an arc generation region, and an arc generation point situated at a tip of a welding wire is displaced upwardly or downwardly along a groove of a base metal.

Abstract: In the present invention, an iron based alloy which contains by mass %: 0.20% or less of C; 6.0 to 16.0% of Cr; 6.0 to 16.0% of Ni and whose martensitic transformation starting temperature (Ms point temperature) is in the range of 0-170° C., inclusive of 0° C. and exclusive of 170° C., is used as a welding material. With respect to a weld metal, the weld metal has a iron alloy composition which contains by mass %: 0.20% or less of C; 3.0 to 13.0% of Cr; 3.0 to 13.0% of Ni and whose martensitic transformation starting temperature (Ms point temperature) is in the range of 50-360° C., inclusive of both 50° C. and 360° C.

Abstract: A method and apparatus for adjusting a zero point of a pressure sensor of an injection apparatus, which method and apparatus enable precise zero-point adjustment for the pressure sensor. Pressure of resin is detected by use of the pressure sensor, while a screw is moved, and a detection value corresponding to a detected pressure is obtained. The zero point of the pressure sensor is adjusted on the basis of the detection value. The detection value is obtained when the screw is moved in a state in which a flight speed is rendered lower than a screw speed. In this case, since the frictional resistance which acts on resin in the vicinity of the inner circumferential surface of the heating cylinder upon movement of the screw can be decreased, loads stemming from the frictional resistance are prevented from serving as disturbance against the detection value. As a result, zero-point adjustment for the pressure sensor can be performed precisely.

Abstract: The invention provides a welding system capable of freely controlling the dispersion and concentration of arc heat over the groove face with an extreamly narrow gap and a high strength and high quality welded joint structure which is formed by this welding system and which is capable of preventing softening/hardening of the structure, the lowering of the toughness thereof and the generation of a crack. According to the welding system, the melting rate of a welding wire is controlled relative to the welding wire feeding rate by changing the characteristic of an arc current so that the range of behavior and the transfer rate of the arc pole (the arc generating main point at a groove surface) are controlled. Further, the welded joint structure consists of a high strength steel having a superfine grain structure with a carbon equivalent of as low as less than 0.

Abstract: A motor-driven injection molding machine comprises an injection device which includes a heating cylinder for heating resin powder therein to melt the resin powder into molten resin and a screw disposed in the heading cylinder for feeding the molten resin in the heating cylinder forward to meter the molten resin. A controller positions, in response to a position detected signal detected by a position detector, the screw at a metering position using an injection servomotor on and immediately after completion of the plasticization and metering process. In addition, the controller rotates, in response to a pressure detected signal detected by a load cell, the screw in the opposite direction using a screw-rotation servomotor on and immediately after the completion of said plasticization and metering process to carry out depressurization of the molten resin in the heating cylinder that is metered ahead of the screw.

Abstract: The invention provides a welding system capable of freely controlling the dispersion and concentration of arc heat over the groove face with an extreamly narrow gap and a high strength and high quality welded joint structure which is formed by this welding system and which is capable of preventing softening/hardening of the structure, the lowering of the toughness thereof and the generation of a crack. According to the welding system, the melting rate of a welding wire is controlled relative to the welding wire feeding rate by changing the characteristic of an arc current so that the range of behavior and the transfer rate of the arc pole (the arc generating main point at a groove surface) are controlled. Further, the welded joint structure consists of a high strength steel having a superfine grain structure with a carbon equivalent of as low a less than 0.

Abstract: In the present invention, an iron based alloy which contains by mass %: 0.20% or less of C; 6.0 to 16.0% of Cr; 6.0 to 16.0% of Ni and whose martensitic transformation starting temperature (Ms point temperature) is in the range of 0-170° C., inclusive of 0° C. and exclusive of 170° C., is used as a welding material. With respect to a weld metal, the weld metal has a iron alloy composition which contains by mass %: 0.20% or less of C; 3.0 to 13.0% of Cr; 3.0 to 13.0% of Ni and whose martensitic transformation starting temperature (Ms point temperature) is in the range of 50-360° C., inclusive of both 50° C. and 360° C.