iROB Feed HA
13 Appendix
BAL.0737.0 • 2019-11-15
EN - 35
13.7 Theoretical welding information
Here you will find helpful information about the various welding procedures.
13.7.1 Welding with endless wire electrodes (MIG/MAG)
Introduction
A MIG system consists of a direct current generator, a device for feeding wire, a wire spool and a gas torch.
Power is supplied via the smelting electrodes (wire with positive polarity) to the arc. In this procedure, the molten metal is transferred
to the workpiece via the arc. Wire feeding is required to supply the molten electrode wire again during welding.
Procedure
There are two transfer methods when welding with shielding gas. They differ in how the beads are shed from the electrode.
In the first method, known as short arc, the electrode makes direct contact with the bath. Next, a short circuit to melt the wire
is triggered, which is interrupted for this reason. Finally, the arc reignites and the cycle repeats (Fig. 1a).
The second method for the transfer of beads is known as spray arc. Beads are shed from the electrode and then reach the
molten bath (Fig. 1b).
Fig. 14
Manual welding system
Wire spool
Wire feeder
Welding torch
Workpiece
Welding
rectifier
Shielding gas
Fig. 15
Short arc cycle and spray arc welding
Power
supply
Voltage
Short
circuit
Ig
nit
es
Arc period
E
xti
ng
ui
shes
Time
Fig. 1a
Fig. 1b
Arc
Bead heating
Bead necking
Bead transfer
Time
