A dissimilar-metal joining tool that places a ring-shaped joining auxiliary member made of iron, on a surface of a workpiece in which a second metal plate made of non-ferrous metal is laminated on a first metal plate made of iron, coaxially with a through-hole penetrates the second metal plate, and that performs arc welding toward an inner hole of the joining auxiliary member, the dissimilar-metal joining tool includes a base attached to a distal end of a robot; an arc welding torch attached to the base; a positioning mechanism provided in the base, and places the inner hole at a joining position in the arc welding torch and holds the joining auxiliary member in a radially-positioned state; and a pressing mechanism presses the joining auxiliary member in the vicinity of an outer peripheral edge.

A method for joining a first part formed of an aluminum material to a second part formed of a steel material by metal inert gas welding and cold metal transfer is provided. An aluminum filler material forms a fillet joint between the parts and provides a structure for automotive body applications, such an aluminum bumper extrusion joined to a steel crush box connection. The first part includes a notch for hiding the start and end of the joint. A transition plate formed of a mixture of aluminum material and steel material can be disposed between the first part and the second part to provide the notch. The second part can include a mechanical fastener further joining the parts together. In another embodiment, the second part includes a plurality of dimples and is welded to the first part along the dimples.

A method of welding a superalloy component includes the following sequential steps. A welding step for welding a cavity using a filler metal in an inert atmosphere, where the cavity is located in the component. A covering step for covering the filler metal and a portion of the component with a weld filler layer in the inert atmosphere. The weld filler layer has a greater ductility than material comprising the component and/or material comprising the filler metal. A second covering step for covering the weld filler layer with a braze material, and subsequently performing a brazing operation. A heat treating step heat treats the component.

A welding parameter derivation device of a welding machine having a torch and a weaving mechanism derives welding parameters in accordance with the cross-sectional shape of a weld portion of a new base metal. A database stores welding parameter data, and a welding parameter computation unit computes welding parameters for the shape of a groove or joint of a new base metal. Based on past welding parameter data for a shape similar to that of a groove or joint of a new base metal, and input data pertaining to the specifications of the welding machine, the computation unit derives welding parameter data for the new base metal, taking into account a parameter of the cross-sectional area of the weld portion formed on the new base metal, the bead height of the weld portion, the quantity of heat inputted to the new base metal, and a torch weaving parameter.

Second member (20) includes a material that is difficult to weld to first member (10). First member (10) is provided with first penetrating part (11) penetrating in a thickness direction. Third member (30) is arc-welded to an inner peripheral surface of first penetrating part (11) and opening surface (10a) of first member (10) via second penetrating part (21) of second member (20). Second member (20) is compressed by flange (31) and first member (10) by solidification contraction of third member (30), and second member (20) is therefore fixed between flange (31) of third member (30) and first member (10).

A welding parameter derivation device of a welding machine having a torch and a weaving mechanism derives welding parameters in accordance with the cross-sectional shape of a weld portion of a new base metal. A database stores welding parameter data, and a welding parameter computation unit computes welding parameters for the shape of a groove or joint of a new base metal. Based on past welding parameter data for a shape similar to that of a groove or joint of a new base metal, and input data pertaining to the specifications of the welding machine, the computation unit derives welding parameter data for the new base metal, taking into account a parameter of the cross-sectional area of the weld portion formed on the new base metal, the bead height of the weld portion, the quantity of heat inputted to the new base metal, and a torch weaving parameter.

Apparatus and method for welding steel boiler tubes in a space restricted area using a pulsed-arc welding process. The process includes the use of a consumable insert ring having a T-shaped profile and flux material to provide deep weld penetration by a GTAW welding machine. Notches in the consumable weld ring allow for visual inspection of tube fit prior to weld.