voestalpine Bohler Welding URANOS NX 2200 SMC Classic Mode D'emploi page 40

OPERATING INSTRUCTIONS
10.3 Continuous wire welding (MIG/MAG)
Introduction
EN
A MIG system consists of a direct current power source, wire feeder, wire spool, torch and gas.
Methods
In MIG welding, two main metal transfer mechanisms are present and they can be classified according to the means by which
metal is transferred from the electrode to the workpiece.
that melts the wire. The short circuit is then broken, re-igniting the arc and repeating the cycle.
I (A)
V (V)
A
B
MIG manual welding system
The current is transferred to the arc through the fusible electrode
(wire connected to positive pole);
In this procedure the melted metal is transferred onto the workpiece
through the arc stream.
The current is transferred to the arc through the fusible electrode
(wire connected to positive pole); in this procedure the melted metal
is transferred onto the workpiece through the arc stream. The
automatic feeding of the continuous filler material electrode (wire)
is necessary to refill the wire that has melted during welding.
1. Torch
2. Wirefeeder
3. Welding wire
4. Workpiece
5. Power source
6. Cylinder
SHORT cycle and SPRAY ARC welding
Another mechanism for metal transfer is called the "SPRAY-ARC"
method, where the metal transfer occurs in the form of very small
t (ms)
drops that are formed and detached from the tip of the wire and
transferred to the weld pool through the arc stream (Fig. 2b).
t (ms)
40