METHOD OF ARC WELDING, SURFACING OR SOLDERING WITH CONSUMABLE ELECTRODE AND CURRENT SOURCE

The inventions relate to the field of arc welding, surfacing or soldering, where a consumable electrode is used including manual arc welding, surfacing and soldering, as well as mechanized arc welding, surfacing and soldering. A method of arc welding, surfacing or soldering with a consumable electrode that is fed into the arc zone at a constant weighted average rate, according to which a periodic change of the arc length takes place, with self-regulation of electrode burning-off, is carried out by maintaining weighted average current density on the electrode at a level less than required for known mechanized welding. The process of electrode melting occurs in the oscillatory mode, with intense increase in current density on the electrode during periods of decreasing the length of the arc when the arc length and arc voltage become smaller than the parameters inherent to the known method of mechanized arc welding, and an abrupt decrease in current density with simultaneous intensive increase in the arc voltage during periods of increase of arc length, while maintaining the ratio of the parameters: during periods of reduction of the arc length, (1)where- increase of the current density on the electrode due to the increase of the welding current, A/mm;- assigned weighted average value of current density, A/mm;- reduction of the instantaneous value of the arc voltage, V;- assigned value of the arc voltage, V, which corresponds to the assigned weighted average value of the current density; 9 and 22 - scalars, and during periods of increased arc length, (2)where- reduction of the current density on the electrode due to reducing the welding current, A/mm; - increase in the instantaneous value of the arc voltage, V, and change in the above actions meeting the ratios (1) and (2) occurs when the instantaneous voltage of the arc corresponds to the ratio, (3)where- nominal (minimum possible) voltage of the arc burning in given processing conditions for a given value of the welding current (arc current); Un - threshold arc voltage, V. Also disclosed is a current source for welding arc for carrying out the method. This leads to the decrease of the standard minimum current density on the consumable electrode to a level significantly lower than for mechanized arc welding while improving the stability of the arc; extension of the scope of application of technologies of mechanized arc welding/surfacing/soldering, reduction of volume of consumption of costly wire of small dia