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 method and an apparatus for chain welding a chain starting from a chain composed of open C-shaped chain links uses a conveying wheel which receives one or more chain links of the chain and positions them for welding. The conveying wheel is a double chain wheel, the two pocket wheels of which receive a respective chain link of two chain strands of the chain. In each sequence of welding of a chain link, the conveying wheel is displaced relative to a welding device transversely with respect to the longitudinal direction of the chain and then occupies a welding position in which a chain link to be welded, as chain link that is vertical in the conveying wheel, faces the welding device and the open ends thereof are welded. This sequence is repeated, allowing that chain links of the two chain strands are alternately welded in the chain wheel.

A method for manufacturing an integrated member and an integrated member manufactured by the method which can improve the joining strength and reduce the manufacturing cost. A method for manufacturing an integrated member by welding a first member formed of aluminum alloy material and a second member formed of ferrous-based material characterized in that the first member contains a predetermined amount of silicon and has a thickness larger than that of the second member. The second member can be pressed against the first member along the thickness direction, and by electrically energizing the pressed-in portion during the pressing period, electric resistance welding can be used. The pressing-in amount is set to a value larger than the thickness of the second member and less than that of the first member. The overlapping margin of the first and second members is set to a value of 0.5 mm or more.

A method for manufacturing an integrated member and an integrated member manufactured by the method which can improve the joining strength and reduce the manufacturing cost. A method for manufacturing an integrated member by welding a first member formed of aluminum alloy material and a second member formed of ferrous-based material characterized in that the first member contains a predetermined amount of silicon and has a thickness larger than that of the second member. The second member can be pressed against the first member along the thickness direction, and by electrically energizing the pressed-in portion during the pressing period, electric resistance welding can be used. The pressing-in amount is set to a value larger than the thickness of the second member and less than that of the first member. The overlapping margin of the first and second members is set to a value of 0.5 mm or more.

A magnet arrangement for a magnetically impelled arc butt welding system, wherein the system is used to weld an airfoil to a platform of a gas turbine. The magnet arrangement includes a first plurality of magnets wherein the magnets are located adjacent a first curved airfoil surface and arranged in a first curved shape corresponding to a shape of the first curved airfoil surface. The magnet arrangement also includes a second plurality of magnets wherein the magnets are located adjacent a second curved airfoil surface and arranged in a second curved shape corresponding to a shape of the second curved airfoil surface such that the first plurality of magnets has a different curvature than the second plurality of magnets. The first and second plurality of magnets guide an electric arc of the system along mating surfaces to heat the mating surfaces to enable the airfoil and platform to be forged together.

A novel copper and steel composite pipe, a manufacturing method, application and a welded structure body is described herein. The novel copper and steel composite pipe includes a copper pipe and a steel pipe. The steel pipe includes a first end, a second end and a middle part. The copper pipe includes a first end and a second end. The length of the copper pipe is less than that of the steel pipe. The copper pipe and the steel pipe are sleeved. The distance from an end surface of the first end of the copper pipe to an end surface of the first end of the steel pipe is less than 10 mm. The second end of the copper pipe is positioned at the middle part of the steel pipe, and the copper pipe and the steel pipe are welded and connected in a way of melting base materials.

A novel copper and steel composite pipe, a manufacturing method, application and a welded structure body is described herein. The novel copper and steel composite pipe includes a copper pipe and a steel pipe. The steel pipe includes a first end, a second end and a middle part. The copper pipe includes a first end and a second end. The length of the copper pipe is less than that of the steel pipe. The copper pipe and the steel pipe are sleeved. The distance from an end surface of the first end of the copper pipe to an end surface of the first end of the steel pipe is less than 10 mm. The second end of the copper pipe is positioned at the middle part of the steel pipe, and the copper pipe and the steel pipe are welded and connected in a way of melting base materials.

To provide a method and apparatus for manufacturing a joined member that inhibit occurrence of cracks in a joined member even when the joined portion is quenched when members are welded together. The method includes placing the first member D and the second member E with a joint target portion Df and a joint target portion Ef being in contact with each other, welding the joint target portions by heating, subjecting the first member D after the welding to a process for inhibiting occurrence of cracks, and tempering a portion where the first and second members have been welded to each other by electromagnetic heating. The apparatus includes a first electrode 11 to contact with the first member D; a second electrode 12 to contact with the second member E; and an induction heating coil 23 for performing induction heating of a portion where a joint target portions Df and Ef have been contacted and joined to each other, and the induction heating coil 23 is placed between the two electrodes 11 and 12 when the induction heating is performed.

To provide a method and apparatus for manufacturing a joined member that inhibit occurrence of cracks in a joined member even when the joined portion is quenched when members are welded together. The method includes placing the first member D and the second member E with a joint target portion Df and a joint target portion Ef being in contact with each other, welding the joint target portions by heating, subjecting the first member D after the welding to a process for inhibiting occurrence of cracks, and tempering a portion where the first and second members have been welded to each other by electromagnetic heating. The apparatus includes a first electrode 11 to contact with the first member D; a second electrode 12 to contact with the second member E; and an induction heating coil 23 for performing induction heating of a portion where a joint target portions Df and Ef have been contacted and joined to each other, and the induction heating coil 23 is placed between the two electrodes 11 and 12 when the induction heating is performed.

Provided are a hot-rolled steel sheet for an electric resistance welded steel pipe and a method for manufacturing the same, an electric resistance welded steel pipe and a method for manufacturing the same, a line pipe, and a building structure. The hot-rolled steel sheet has a chemical composition containing, by mass %, C: 0.030% or more and 0.20% or less, Si: 0.02% or more and 1.0% or less, Mn: 0.40% or more and 3.0% or less, P: 0.050% or less, S: 0.020% or less, N: 0.0070% or more and 0.10% or less, and Al: 0.005% or more and 0.080% or less, the balance being Fe and incidental impurities, in which N dissolved in steel is contained in an amount of 0.0010% or more and 0.090% or less, and letting a sheet thickness be t, a steel microstructure at a ?t position has an average grain size of 20.0 ?m or less.