The purpose is to determine occurrence of expulsion in seam welding with high accuracy. A welding determination device includes: a measurement unit configured to measure temperature of a joint portion between strip-shaped sheets (for example, steel strips) to be joined by seam welding; and a determination unit configured to, based on a measurement result by the measurement unit, calculate an average temperature T.sub.ave and a temperature difference T of the joint portion and, when the average temperature T.sub.ave is more than or equal to a first threshold value that is set according to the sheet thickness of each of the strip-shaped sheets and the temperature difference T is more than or equal to a second threshold value, determine that expulsion has occurred at the joint portion.

A method for joining of at least two materials, non-weldable directly to each other with thermal joining processes in a lap joint configuration includes a two step sequence including a first step to apply a thermomechanical or mechanical surface protection layer on the surface of a (stainless) steel substrate and a second step where, a thermal joining process is used to weld the sprayed layer with an applied aluminum sheet without having brittle intermetallic phases in the whole material configuration.

A method for joining of at least two materials, non-weldable directly to each other with thermal joining processes in a lap joint configuration includes a two step sequence including a first step to apply a thermomechanical or mechanical surface protection layer on the surface of a (stainless) steel substrate and a second step where, a thermal joining process is used to weld the sprayed layer with an applied aluminum sheet without having brittle intermetallic phases in the whole material configuration.

Provided is a welding monitoring apparatus that monitors a welding state of a V-convergence region in which a strip-shaped metal sheet is converged in a V-shape, when the metal sheet is cylindrically formed while being conveyed, and both side edges of the metal sheet are heated and melted in a manner of being butted each other while being converged in the V-shape, such that an electric resistance welded steel pipe is manufactured. This welding monitoring apparatus includes an image capturing unit that captures images of a region including the V-convergence region in time series; and an image processing unit that extracts a welding point based on the images captured in time series and detects the presence or absence and a position of irregular arcing at the welding point or on an upstream side of the welding point.

A method for manufacturing a sandwich panel as a semi-finished product where at least one layer of a non-metallic material is positioned between at least two metallic layers. At least one of the metal layers is shaped into a three dimensional layer and the metal layers are material closured to each other by a tack weld on the metallic contacts between the metallic layers to enable resistance weldability of the semi-finished product in order to connect the semi-finished product to a desired combination of solutions.

A method for manufacturing a sandwich panel as a semi-finished product where at least one layer of a non-metallic material is positioned between at least two metallic layers. At least one of the metal layers is shaped into a three dimensional layer and the metal layers are material closured to each other by a tack weld on the metallic contacts between the metallic layers to enable resistance weldability of the semi-finished product in order to connect the semi-finished product to a desired combination of solutions.

Welding apparatus, for example for a workpiece, comprises resistance welding electrode wheels which form a weld seam between components of the workpiece. The formed weld is monitored by an ultrasonic probe which is situated behind the rollers with reference to the weld direction. The ultrasonic probe comprises a linear phased array of piezoelectric elements. The probe enables real-time monitoring of the welding process, with the facility to adjust the process to correct deviations.

An apparatus (10) for joining a predetermined geometrical profile shape from a sheet material (SM) includes a positioning assembly (12) including a base member (14) and a frame (16) that is operable to receive the sheet material (SM), to configure the sheet material in a predetermined orientation and to linearly translate the sheet material along a process direction (20). A Z-bar (22) is configured to guide a first longitudinal edge (FE) and second longitudinal edge (SE) of the sheet material (SM) into adjacent alignment along the process direction (20). A welding and forging assembly (60) welds and then forges a seam between the first longitudinal edge (FE) and the second longitudinal edge (SE) of the associated sheet material (SM).

The invention relates to the thermal creation of a part, including steps of: using at least one first and one second metal plate (30, 31), hollow-forming the first plate so as to form at least part of said inner wall, and hollow-forming the second plate (31) so as to form at least part of said outer wall. During the forming, the shapes of the first and second plates are adjusted such that they can be placed in contact with each other while leaving a space therebetween inside said periphery, and then the first and second plates are placed in a low-pressure and/or controlled-atmosphere chamber (65), where said plates are brought together and peripherally sealed together such that, in said space, a low-pressure and/or controlled-atmosphere enclosure is created.

This seam-welding device carries out seam welding while repeating one cycle comprising a melting period, an interruption period, and a heating period implemented either before or after the interruption period. A welding current is applied between a pair of roller electrodes so as to form a welded part between workpieces during the melting period, the application of the current between the roller electrode pair is interrupted so as to solidify the welded part during the interruption period, and a heating current smaller than the welding current is applied between the roller electrode pair so as to heat the laminated body within a solidification temperature range of the welded part during the heating period. Consequently, even when the welding speed is increased, formation of cracks and spatter is effectively suppressed such that a high-quality joined product is obtained.