Method and apparatus for arc welding with melting electrode

An arrangement for pulsed gas metal-arc welding comprising a welding-power unit, a wire-feed mechanism, adapted for in the main non-short-circuiting material transfer from the electrode to the workpiece by periodically increasing the welding current to a pulse current of such size and duration that the current density in the electrode causes sufficient electromagnetic forces in order to separate one drop for each pulse, and a regulator comprising an arrangement being configured to regulate the power supply for the arc for stabilizing the arc length mainly on the basis of a measured arc voltage, wherein the regulator is also adapted to detect arc-voltage decreases and current increases indicating short-circuits of the arc, and wherein the power regulator is configured to give an additional increase of the welding power for each short-circuit detected.

A method for pulsed gas metal-arc welding with an electrode fed to the welding site continuously at a given rate, comprising the steps of regulating fusion power such that fusion conditions are adapted in such a manner that the material transfer from the electrode to the workpiece takes place essentially without short-circuiting drops by the welding current being periodically increased to a pulse current of such size and duration that the current density in the electrode causes sufficient electromagnetic forces in order to separate one drop for each pulse, and stabilizing the arc length by regulating the power supply for the arc, by means of an arc length regulator, mainly on the basis of a measured arc voltage, and detecting each short-circuit, and adjusting the arc length regulator to thereby increase the fusion power over an existing fusion power for each short-circuit detected.