Electric resistance welding

About: Electric resistance welding is a research topic. Over the lifetime, 16761 publications have been published within this topic receiving 154851 citations.

Out-of-position friction stir welding of high melting temperature alloys

Abstract: A system and method for performing friction stir welding of non-planar materials having high melting temperatures, wherein a process is provided for performing longitudinal and radial welds on objects such as pipes, flanges, tanks, and shrouds, and wherein an active or passive mandrel provides support for the friction stir welding process.

Method for continuously regulating or tracking a position of a welding torch or a welding head

Abstract: The invention relates to a method for continuously regulating or tracking a position of a welding torch (10) or a welding head, in relation to a welded joint which is to be produced on a workpiece (16). According to said method, the welding torch (10) which is positioned at a distance from the workpiece (16) or the welded joint executes a pendulum motion which overlays its linear welding motion, while the state variables that are temporally modified, in particular an ohmic resistance or a current and/or a voltage, are detected. In order to regulate or track the position of the welding torch (10), the lateral deviation of the welding torch (10) in relation to the welded joint, in particular in relation to the centre of the welded joint and/or the height of the welding torch (19) above the workpiece (16) or the welded joint, is derived from the detected actual value or signals. The measured value of at least one measuring signal, in particular of the state variable, is detected based on periodically recurring process phases of a welding process, at defined times and/or states of said periodically recurring welding process.

Effects of current on droplet generation and arc plasma in gas metal arc welding

Abstract: In gas metal arc welding (GMAW), a technology using pulsed currents has been employed to achieve the one-droplet-per-pulse (ODPP) metal transfer mode with the advantages of low average currents, a stable and controllable droplet generation, and reduced spatter. In this paper, a comprehensive model was developed to study the effects of different current profiles on the droplet formation, plasma generation, metal transfer, and weld pool dynamics in GMAW. Five types of welding currents were studied, including two constant currents and three wave form currents. In each type, the transient temperature and velocity distributions of the arc plasma and the molten metal, and the shapes of the droplet and the weld pool were calculated. The results showed that a higher current generates smaller droplets, higher droplet frequency, and higher electromagnetic force that becomes the dominant factor detaching the droplet from the electrode tip. The model has demonstrated that a stable ODPP metal transfer mode can be achieved by choosing a current with proper wave form for given welding conditions.

Controller for resistance welding machine

Abstract: An inverter-type resistance welding machine includes a keyboard for inputting desired welding current command data corresponding to commanded values, a display unit for displaying, in the form of a numerical table or graph, the welding current command pattern data inputted by the keyboard, a memory for storing a plurality of the welding current command patterns set by the keyboard and from which these patterns are read out in response to a selection command from the keyboard to serve as a control command of the inverter, and acceptability decision means which successively accepts detected welding current at the time of welding for making a comparison with the reference welding current command pattern over a full range of values, checking correlation between the detected welding current and the reference welding current command pattern and determining whether the detected welding current lies within a predetermined tolerance.