A metal composite and a metal joining method that are capable of suppressing an influence on joining strength of a friction stir welded section due to a tool hole formed when a tool is extracted, in the case in which two metals are joined through friction stir welding. In an overlapping section in an axial direction in which a first shaft and a second shaft overlap in the axial direction, an inscribed section in which the first shaft and the second shaft come in contact with each other and an non-inscribed section in which the first shaft and the second shaft do not come in contact with each other are formed. In the non-inscribed section, a plate thickness of the second shaft is decreased. Then, a starting point of a friction stir welded section is formed in the inscribed section, and an endpoint is formed in the non-inscribed section.

A method providing a first tubular workpiece having a first weld surface at an end thereof, and a second tubular workpiece having a second weld surface at an end thereof; aligning the workpieces on a common axis with the weld surfaces facing each other, rotating one workpiece about the axis relative to the other workpiece, and engaging the first and second weld surfaces such that the rotation raises the temperature at the weld surfaces to create a weld interface; and ceasing the rotation and allowing the weld interface to cool to weld the workpieces together at the interface. The first weld surface is an apex region of an annular projection at the end of the first workpiece, on a longitudinal section through the aligned workpieces the annular projection having a profile in which radially inner and outer side surfaces of the annular projection taper towards the apex region.

Pipe flange alignment leveling pins are disclosed to square a flange. The pins include a first and a second cylindrical magnet each configured to have a hollow axis and a positive radial pole and a negative radial pole. A first and a second chamfered hollow pin are engineered to axially receive a respective cylindrical magnet, the chamfer of each pin on an end configured complementary to a flange hole chamfer. A non-magnetic core is engineered to axially slide in and out of the hollow axis of the magnets received into respective pins wherein each of a pair of apparatus resemble a bow tie in cross section configured to align a pair of flanges in two places for a level operation. A level is set across a first and a second assembly of chamfered pins to determine a level flange ready for welding.

A method for manufacturing a bonded article having long bonding length and high strength. A first bonding target member and a second bonding target member having a hole portion for receiving the first member are provided. Pressing force is applied between the two members with the first member received in the hole portion, and a current is applied to a bonding target portion between the two members with the pressing force applied. The two members are of materials with different melting points. One of the two members, having lower melting point, has a heat capacity increasing portion in the vicinity of the target portion. The one of the members has a taper face at the target portion, and the heat capacity increasing portion has a face extending from the taper face. The force applying step is performed with the other member positioned not to contact the heat capacity increasing portion.

Certain embodiments of the disclosed technology provide systems and methods for an improved header and corresponding port associated with a transducer assembly. The header and port define mating threaded portions, thread stop portions, and a weld gap region. The thread stop portions are configured to mate and maintain a pre-loading tension between the threaded portions during and after applying a weld in the weld gap region. The weld gap region is configured to have a predetermined gap distance such that the weld seals the transducer without stress in the weld. The mating of the first and second thread stops are configured to maintain at least a portion of the pre-loading tension.

To provide a metal bonded product wherein a large bonding area can be provided to achieve high bonding strength and coaxial accuracy can be easily achieved needing no positioning jig. A first taper portion 16 is formed on a side wall surface of the opening 13 of the ring-shaped metal member 12, and multiple step-shaped bonding surfaces are formed thereon. An end of the cylindrical portion 11 has a second taper portion 17 with the same chamfer angle as that of the first taper portion 16 of the ring-shaped metal member 12. The ring-shaped metal member 12 and the cylindrical metal member 11 are bonded to each other by press-fitting the cylindrical portion of the cylindrical metal member 11 in the opening 13 of the ring-shaped metal member 12 while applying a current to cause the side wall portion of the cylindrical portion of the cylindrical metal member 11 and the multiple step-shaped bonding surfaces of the first taper portion 16 to undergo plastic flow.

A joint-site structure for components to be connected by overlap friction welding. At least one step of at least one component, on which an axially set-back ring-shaped joining surface is situated, is provided with a radial undercut, in such a manner that on the face side, a region of this step that is unchanged in diameter forms a radial support ridge, which is connected with the at least one component by way of a heat throttle that is reduced in cross-section. The length of each step is designed in such a manner that when the face surface of the one component makes contact with the ring-shaped joining surface of the other component, the other face surfaces of these components, which surfaces lie opposite one another in the same radial position, are still exposed until completion of the friction-welding process.

The present invention provides a submerged arc welding method attempting to enhance toughness of a welded zone with low heat input and capable of achieving deep penetration and a sufficiently wide bead width in welding a thick material at a weld speed of 3 m/min or less. In the submerged arc welding method, a first electrode at the head in a welding direction has a wire diameter of 3.9 to 4.1 mm, two electrodes are arranged on both sides holding a weld line therebetween at the tail end in the welding direction, the wire tip positions of the two electrodes on a surface of the steel plate are arranged on the same line vertical to the weld line, and a distance W (mm) between each of the wire tip positions and the weld line is 5 to 20 mm.

Reduced tube pitch within a shell-and-tube heat exchange reactor such as, for example, an EO reactor, is provided by utilizing a welding material that has a high tensile (i.e., a tensile strength of greater than 600 MPa). Reduced tube pitch allows for more elongated tubes (the tubes are filled with a catalyst) to be present in a reactor, and thus a smaller reactor can be manufactured. Notably, the use of a high tensile strength welding material allows the implementation of a small welding groove located between a beveled sidewall of a beveled upper portion of an opening provided in a tube sheet overlay material (that is located atop a tube sheet) and an outermost sidewall of the elongated tube passing through the opening in the tube sheet overlay material.

A machine component includes a first region having a first linear expansion coefficient, and a second region having a second linear expansion coefficient greater than the first linear expansion coefficient and joined to the first region. A region including an outer periphery of an interface between the first region and the second region is inclined toward the second region side over the entire periphery. On a surface of the first region, a groove is formed to extend along the outer periphery of the interface.