An electric resistance welded steel pipe, and a method for manufacturing the same are provided. An electric resistance welded steel pipe has a welded portion that includes a heat-affected zone having a steel microstructure principally including a bainitic ferrite phase and/or a bainite phase. The steel microstructure at half the wall thickness includes a bainitic ferrite phase and/or a bainite phase in a total area ratio of 90% or more. In the steel microstructure located 1 mm in the wall thickness direction, the bainitic ferrite phase and/or the bainite phase has an average grain size of 20 μm or less. The average grain size of the bainitic ferrite phase and/or the bainite phase located 1 mm in the wall thickness direction is 0.5 times or more and 2 times or less the average grain size of the bainitic ferrite phase and/or the bainite phase at half the wall thickness.

A welding system including a welding electrode, a closed-loop cooling device, and a vent. The closed-loop cooling device is configured to cool the welding electrode. The closed-loop cooling device includes a pump and a water line. The vent is located along a path of the water line. The vent is configured to release air trapped within the water line.

Apparatus for controlling a welding station used for welding seams extending along cylindrical can bodies, the welding station comprising a pair of welding rolls and a calibration unit for causing a desired cylinder overlap during welding. The calibration unit is adjustable along at least three different adjustment axes. The apparatus comprises: a weld monitor configured to monitor welded seams and provide an electrical signal indicative of weld thickness at a series of predetermined points along the seam length; a controller configured to receive said signal and to generate one or more control signals; and adjustment mechanisms for coupling to the calibration unit, or forming part of the calibration unit. The adjustment mechanisms are configured to receive the signal(s) and to be responsive thereto to adjust the calibration unit relative to one or more of said three adjustment axes, to provide the desired cylinder overlap and/or a desired weld quality.

A welding system including a welding electrode, a closed-loop cooling device, and a vent. The closed-loop cooling device is configured to cool the welding electrode. The closed-loop cooling device includes a pump and a water line. The vent is located along a path of the water line. The vent is configured to release air trapped within the water line.

Apparatus for controlling a welding station used for welding seams extending along cylindrical can bodies, the welding station comprising a pair of welding rolls and a calibration unit for causing a desired cylinder overlap during welding. The calibration unit is adjustable along at least three different adjustment axes. The apparatus comprises: a weld monitor configured to monitor welded seams and provide an electrical signal indicative of weld thickness at a series of predetermined points along the seam length; a controller configured to receive said signal and to generate one or more control signals; and adjustment mechanisms for coupling to the calibration unit, or forming part of the calibration unit. The adjustment mechanisms are configured to receive the signal(s) and to be responsive thereto to adjust the calibration unit relative to one or more of said three adjustment axes, to provide the desired cylinder overlap and/or a desired weld quality.

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 for creating a clad structure, comprising providing a substrate having an inner surface and an outer surface; providing a cladding material, wherein the cladding material is placed on the inner surface of the substrate, the outer surface of the substrate, or both; providing a surface activation material that is disposed between the substrate and the cladding material; providing at least one resistance welding device, wherein the at least one resistance welding device includes at least one electrode wheel that directly contacts the cladding material, and wherein the at least one resistance welding device generates resistance heating and pressure sufficient to melt the surface activation material and form a localized bond between the substrate and the cladding layer; and traversing the at least one electrode wheel across the cladding material and substrate to propagate the localized bond between the cladding material and the substrate and create a clad structure.

For the determination of the welding current to be used for the resistance welding of the overlap seam of container bodies, welding with a test body is carried out with a changing strength of welding current which in the test body produces a varying welding of the seam. The current strength varies from welding of this seam with a too high temperature to welding with a too low temperature. Along with this the welding current strength used in the welding is determined so that it is further determined at which point of the seam the welding has been accomplished and with what strength of welding current. By means of a mechanical and/or optical investigation of the welded seam it can then be easily determined where the seam has been correctly welded for the series production of container bodies from the same sheet material as the test bodies. When such a point or such a region of the seam is known the welding current used in the test welding can be taken as the welding current for serial production.

An automatic welding machine comprising clamping units, pushing pneumatic cylinders, a compression drive, and pressing and supplying welding current contact welding rollers. The automatic welding machine also comprises a die positioning of the ribs with respect to the pipe and clamping units, windows for the passage of rollers, and a mechanism for positioning the die. The clamping units have a mechanism for adjusting the position of the longitudinal axis of the compression drive of the roller, consisting of a compression drive guide, two regulators, a compression drive housing, a ball joint assembly, an adjusting lock nut, a fixing screw, and two bronze crackers. A mechanism for adjusting the contact welding roller comprises a roller, bushings, nuts, cheeks, and threaded elements.

An electric resistance welded steel pipe, and a method for manufacturing the same are provided. An electric resistance welded steel pipe has a welded portion that includes a heat-affected zone having a steel microstructure principally including a bainitic ferrite phase and/or a bainite phase. The steel microstructure at half the wall thickness includes a bainitic ferrite phase and/or a bainite phase in a total area ratio of 90% or more. In the steel microstructure located 1 mm in the wall thickness direction, the bainitic ferrite phase and/or the bainite phase has an average grain size of 20 m or less. The average grain size of the bainitic ferrite phase and/or the bainite phase located 1 mm in the wall thickness direction is 0.5 times or more and 2 times or less the average grain size of the bainitic ferrite phase and/or the bainite phase at half the wall thickness.