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.

A method of producing an endless metal ring by butting and welding ends of a steel plate includes a welding process in which, while the ends of the steel plate are heated at a temperature lower than a melting temperature, the ends are pressed against each other and welded by butt welding; and a heat treatment process in which heating is performed at an austenite transformation temperature or lower after the welding process.

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.

A sensor element includes: an element body including, for example, a thermistor; paired lead wires drawn out from the element body; and stranded wires that are each obtained by twisting a plurality of core wires and are joined to the respective paired lead wires in a welding region. The welding region includes a main joining region provided in a predetermined region in an axis direction, and sub joining regions adjacent to the main joining region, and joining strength of each of the lead wires and the corresponding stranded wire is higher in the main joining region than in the sub-joining region.

A vehicle pillar structure and a method for manufacturing a vehicle pillar in which, in a pillar framework, a member is easily disposed on a surface facing a transparent panel in an overlapping manner, while reducing the width of the pillar framework, and a corner butt portion on the side of the transparent panel has increased welding accuracy are provided. A flange of an outer panel and a flange of an inner panel are welded by spot welding. An end surface of a front end of the inner panel is butted against an inner surface end of the outer panel, and is welded thereto by laser welding, such that welding beads are thereby linearly formed at established intervals.

A method for resistance welding at least three steel sheets, a weld structure produced by resistance welding at least three steel sheets and a method for determining weldability solutions when resistance welding at least three steel sheets in a stack are provided. By applying a layer of adhesive/sealer material between a thicker outer sheet of steel and an adjacent thicker inner sheet, thereby generating extra heat that increases penetration into a thinner outer sheet but with no layer of adhesive/sealer material between a thinner outer sheet and an adjacent thicker inner sheet, current density drop issues of a current process are addressed.

There is provided a component joining structure that includes: a resin component; a metal tip that is provided in the resin component by insert molding, and that includes protruding portions that protrude from the resin component; and a metal component that is spot welded to the protruding portions, and that is joined to the resin component by an adhesive agent that is provided in gaps formed, by the protruding portions, between the resin component and the metal component.

An electric-resistance-welded stainless clad steel pipe or tube that is excellent in both the fracture property of the weld and the corrosion resistance of the pipe or tube inner surface as electric resistance welded without additional welding treatment such as weld overlaying after electric resistance welding is provided. An electric-resistance-welded stainless clad steel pipe or tube comprises: an outer layer of carbon steel or low-alloy steel; and an inner layer of austenitic stainless steel having a predetermined chemical composition, wherein a flatness value h/D in a 90 flattening test in accordance with JIS G 3445 is less than 0.3, and a pipe or tube inner surface has no crack in a sulfuric acid-copper sulfate corrosion test in accordance with ASTM A262-13, Practice E, where h is a flattening crack height (mm), and D is a pipe or tube outer diameter (mm).

To improve quality control of welding, there is included in resistance welding: a magnetic field measuring unit (205) disposed around a welded part and configured to measure a local current at the welded part; a high-speed camera (202) configured to capture an image for measuring local temperature at the welded part from variation of luminance of emission by capturing light emission state of the welded part; a comparison determination unit (106) configured to determine whether or not at least one of current information and temperature information has an abnormal value by comparing the current information calculated based on magnetic field information acquired from the magnetic field measuring unit with past current information and comparing the temperature information measured from an image of the high-speed camera (202) with past temperature information.

Provided is an automotive member, or particularly, a steel sheet having a tensile strength exceeding 900 MPa. The automotive member has a resistance weld for fixing two or more steel sheets containing a predetermined composition, in which a maximum hardness (HV.sub.BM) in a heat-affected zone of the resistance weld is at least 1.1 times hardness (HV.sub.W) of a nugget in the resistance weld formed in a softest steel sheet of a sheet set during resistance welding, and furthermore, an average grain size of a steel sheet structure of the heat-affected zone within 2 mm in a direction at a right angle to a sheet thickness from an end part of the nugget of the high-strength steel sheet is 3 m or less, and a minimum hardness (HV.sub.min) in the heat-affected zone is at least 90% of hardness (HV.sub.) of the high-strength steel sheet before the resistance welding.