Pulsed arc and deposition welding of workpieces - where electronic circuits permit replacement of non-consumable electrodes by consumable electrodes, increasing productivity

摘要

In the main current circuit (A) of the appts. is an adjustable, single-phase transformer, the prim. of which is connected to the mains supply; whereas the sec. is connected to a controllable bridge rectifier using thyristors supplied with signals from a main current control circuit (B). The positive pole of the rectifier is connected via a choke coil with variable non-linear inductance to an electrode, whereas the negative pole of the rectifier is connectd to the workpiece. Between the poles of the rectifier is an adjustable resistor controlling the idling output voltage. Circuits (A, B) include electronic components so the arc is fed with a current on which a d.c. pulse is superimposed, the front flank of each pulse rising in a linear manner, but the rear flank falling exponentially. Productivity can be increased threefold. In welding AlMg alloys with consumable electrodes, the mechanical properties of the welds attain 90% of the properties of the base metal.