Effects of parameters on flash welding using a magnetically controlled arc

Flash welding is used more than upset welding because of greater weld strength, no need for special preparation of weld surface, lower power demand with less power consumption, faster speed and smaller upset, and less heat in the work since mostheat appears at the interface. It is possible to weld dissimilar metals of widely differing melting points since flashing may be continued until both metals have reached their individual fusing temperatures. In this process the parts are brought together lightly with current flowing, and then separated slightly; a flashing action is created at the interface. This heats them to their fusion temperature and permits the pressure which is then applied to force the fused areas together and form the weld. In this study, the arc, which is initiated at the heating phase was rotated along the surfaces of the tubes to be welded by means of an external magnetic field to supply a uniform heating. The joints produced by the application of different welding heats and upset forces were mechanically tested and also examined under light-microscope. As a result, optimum parameters for flash welding of thin walled tubes were obtained.