Disclosed is a welded structural member production method comprises: a first preparation step of preparing a cross-sectionally hat-shaped first metal workpiece which has a first base wall, a pair of first standing walls and a pair of flanges; a second preparation step of preparing a cross-sectionally U-shaped second metal workpiece which has a second base wall, and a pair of second standing walls; a positioning step of positioning the first metal workpiece and the metal workpiece in such a manner that each of two pairs of distal edges of the second standing walls and inner edge regions of the flanges are butted against each other; and a joining step of externally welding a butted region of each of the pairs of the distal edges of the second standing walls and the inner edge regions of the flanges to thereby join the first and second metal workpieces together.

The present invention is a weld line-detecting method when fillet welding by an industrial robot including a welding torch is taught. The welding torch on which an angle sensor having a contactor is attached is moved toward a welding object, angle information obtained when the contactor is in contact with the welding object is transmitted to the industrial robot, and the industrial robot moves the welding torch based on the angle information so that the angle of the contactor becomes zero. These operations are repeated, and the welding torch is moved toward a fillet part along the surface of the welding object. When the contactor arrives at the fillet part, a signal indicating that the contactor is pressed in the axial direction of the contactor is transmitted to the industrial robot. The industrial robot detects that the contactor arrives at the position to be welded on the weld line.

The present invention is a weld line-detecting method when fillet welding by an industrial robot including a welding torch is taught. The welding torch on which an angle sensor having a contactor is attached is moved toward a welding object, angle information obtained when the contactor is in contact with the welding object is transmitted to the industrial robot, and the industrial robot moves the welding torch based on the angle information so that the angle of the contactor becomes zero. These operations are repeated, and the welding torch is moved toward a fillet part along the surface of the welding object. When the contactor arrives at the fillet part, a signal indicating that the contactor is pressed in the axial direction of the contactor is transmitted to the industrial robot. The industrial robot detects that the contactor arrives at the position to be welded on the weld line.

The present invention provides a fillet welded joint and a method of production of a fillet welded joint which can raise the productivity of the method of production of a fillet welded joint and a fillet welded joint without sacrificing the strength against fatigue fracture of the welded structural member. The fillet welded joint of the present invention is a fillet welded joint formed by fillet welding at least two metal members, wherein, on the surface of at least one of the metal members, the fillet welded joint comprises a press bead of a rib-shaped projection provided by press-forming so as to project upward to the side having a weld bead formed by the fillet welding, and part of the press bead contacts or overlaps the weld bead.

A method for producing a composite filter tube and filter element made of a multilayer metal mesh and metal powders, including: knitting to obtain metal meshes of different mesh numbers, obtaining a layered structure by means of a lamination method, then putting the layered structure in a vacuum furnace for sintering processing, sintering a metal composite layer to obtain a composite filter sheet and tube made of a multilayer metal mesh and metal powders with a multilayer metal mesh as a structure support layer and a metal powder sinter structure as a filter layer, then rolling the composite filter sheet and tube into a tubular filter element by using a shaping machine, and welding to obtain a composite filter tube and filter element product made of a multilayer metal mesh and metal powders.

A lap fillet arc-welded joint produced by overlapping two metal sheets and welding an end portion of one sheet of the two metal sheets to a surface of the other sheet along the end portion of the one sheet includes a protruding curved potion being bead-shaped and protruding from the surface of the other sheet; and a weld toe positioned on a top portion of the protruding curved portion.

A gas-shielded arc welding method is disclosed and includes joining steel materials together by narrow-gap multilayer welding. A groove between the steel materials has an groove angle ? of 20? or less, and a root gap G (mm) that is a gap at a lower portion of the groove is 7 to 15 mm. Root pass is performed in one pass using a ceramic-made backing material at a welding current I (A) of 250 to 400 A and a welding voltage V (V) of 25 to 45 V while a value [Q/G] obtained by dividing a welding heat input Q (KJ/mm) computed using a prescribed formula by the root gap G (mm) is controlled within a range of 0.32 to 0.70.

A welded assembly includes a first object, a second object, and an interlayer. The interlayer is an ESD coating deposited on the first object, and the second object is welded to the coating. The second object may be a material that has thermally sensitive properties, such as a shape-memory material. The second weld may also be made by ESD. The interlayer may be made of more than one layer. The layer or layers may be deposited of a material chosen for its compatibility with one, the other, or both of the material of the first object and the material of the second object.

A welded assembly includes a first object, a second object, and an interlayer. The interlayer is an ESD coating deposited on the first object, and the second object is welded to the coating. The second object may be a material that has thermally sensitive properties, such as a shape-memory material. The second weld may also be made by ESD. The interlayer may be made of more than one layer. The layer or layers may be deposited of a material chosen for its compatibility with one, the other, or both of the material of the first object and the material of the second object.

A welding method for obtaining a lap fillet welded joint excellent in tensile strength, without causing an increase in welding deformation, not fracturing at the weld metal when a tensile load is applied, that is, a method of overlaying at least scheduled welding locations of a first steel sheet with a tensile strength of 780 MPa or more and a second steel sheet and fillet welding an end part of the first steel sheet and a surface of the second steel sheet, characterized by providing a reinforcing part at a surface of the first steel sheet at the opposite side to the surface to be overlaid with the second steel sheet and fillet welding one end part of the reinforcing material and the surface of the first steel sheet and by fillet welding the end part of the reinforcing part, the end part of the first steel sheet, and the surface of the second steel sheet so as to be covered by the weld metal.