The present invention provides a spot welding method for a member to be welded constituted of a plurality of steel sheets that are overlapped with each other at at least a welding zone, in which at least an overlapped face of at least one of the plurality of steel sheets at the welding zone is coated with zinc plating, a total sheet thickness t (mm) of the plurality of steel sheets is 1.35 mm or more, a squeeze time St (seconds) from the time when welding electrodes are brought into contact with the member to be welded to the time when electric current flow for welding starts satisfies “0.020≤St”, and a hold time Ht( seconds) after welding from the time when electric current flow for welding between the welding electrodes ends to the time when the welding electrodes and the member to be welded are brought out of contact satisfies “0.015t.sup.2+0.020≤Ht”.

A weld joint manufacturing method of the present disclosure includes performing current-passing through an aluminum-plated steel sheet provided with an aluminum plating layer while moving a pair of wheel electrodes relative to the aluminum-plated steel sheet by sandwiching the aluminum-plated steel sheet between the pair of wheel electrodes and rotating the pair of wheel electrodes in a circumferential direction; and welding a part of the aluminum-plated steel sheet, where the current-passing has been performed, and another steel sheet, in an overlapped state of the aluminum plating layer with the other steel sheet.

A method of forming an assembly includes providing a metallic first workpiece having base and a first layer disposed on the base and adhering a second layer onto the first layer. One of the first and second layers is formed of a zinc-based material formed of at least a majority of zinc, and the other of the first and second layers is formed of a metallic alloying material having a melting point higher than the melting point of the zinc-based material. Preferably, the first layer is formed of the zinc-based material, and the second layer is formed of the metallic alloying material with the higher melting point. A metallic second workpiece is disposed in contact with the second layer. A welding operation is performed to join the first workpiece to the second workpiece. A welded assembly is also provided.

Method for joining of at least two unweldable materials, non-weldable directly to each other with thermal joining processes in a lap joint configuration, where a two step sequence is used consisting of a first step to apply a thermomechanical or mechanical surface protection layer on the surface of an unweldable material and a second step, where a thermal joining process is used to joint the sprayed layer with an applied layer sheet.

A method for producing a welded metal blank (16) includes cutting a first initial metal sheet (1) and a second initial metal sheet (3) from a first and second metal strip (4); joining the first and second initial metal sheets (1,3) by welding so as to obtain an initial welded metal blank (9), the initial welded metal blank (9) comprising a weld joint (10) joining the first and the second initial metal sheets (1,3); and cutting said initial welded metal blank (9) by a process involving metal melting so as to obtain at least one final welded metal blank (16) comprising a first metal blank portion (17) and a second metal blank portion (18) joined by a weld joint portion (19) consisting of a portion of the weld joint (10) obtained during the joining step.

A method for fusing an electrical conductor to a film pad circuit including the steps of: providing an electrically inert substrate having a first surface and an opposing second surface; applying an electrically conductive film to the second surface of the electrically inert substrate; applying an electrically conductive member to the electrically conductive film; placing an electrical conductor on the first surface of the electrically inert substrate; and fusing the electrical conductor to the conductive member.

A method of joining a multiple member work-piece includes providing a first steel work-piece having a first electrical resistivity and a second steel work-piece having a second electrical resistivity that is lower than the first electrical resistivity. A third material is disposed in contact with the second steel work-piece. The third material has an electrical resistivity that is greater than the second electrical resistivity. The method includes resistance welding the first and second work-pieces together. The third material may be in the form of a rivet, a third work-piece, or a coating material disposed between the first and second work-pieces. A bonded assembly includes steel members and a third material being bonded together, wherein the electrical resistivity of the second member is lower than the electrical resistivity of the first member, and the third material has an electrical resistivity that is greater than the electrical resistivity of the second member.

A pre-assembled insulated weld backing ring for a tubular section of the pipeline. The weld backing ring includes a metal cylinder and an insulation layer. The metal cylinder has a ring-shaped anterior portion and a ring-shaped raised posterior portion with a step therebetween. The posterior portion has a larger diameter than the anterior portion to define an insulation pocket. The insulation layer is positioned on the external surface of the metal cylinder. The insulation layer is made of an insulated material positioned in the insulation pocket to define a protective barrier to protect the tubular section during welding. The weld backing ring may also include a second metal cylinder positioned on the insulation layer. The weld backing ring may be pre-assembled by applying a tubular metal section material to a sheet of metal and rolling the sheet of metal to form the metal cylinder.

A method of projection welding hardware to a plated steel sheet for hot stamping, may include pressing hardware and a plated steel sheet in a state in which a welding projection on the hardware is in contact with the plated steel sheet, supplying a primary current to the hardware and the plated steel sheet in a state in which they are pressed, and supplying a secondary current to the hardware and the plated steel sheet.

A method of resistance spot welding a workpiece stack-up that includes an aluminum workpiece and an overlapping adjacent steel workpiece so as to minimize the thickness of an intermetallic layer comprising FeAl intermetallic compounds involves providing reaction-slowing elements at the faying interface of the aluminum and steel workpieces. The reaction-slowing elements may include at least one of carbon, copper, silicon, nickel, manganese, cobalt, or chromium. Various ways are available for making the one or more reaction-slowing elements available at the faying interface of the aluminum and steel workpieces including being dissolved in a high strength steel or being present in an interlayer that may take on a variety of forms including a rigid shim, a flexible foil, a deposited layer adhered to and metallurgically bonded with a faying surface of the steel workpiece, or an interadjacent organic material layer that includes particles containing the reaction-slowing elements.