Table of Contents
Advertisement
Typical Metal Transfer Mode
Process
Metal Inert Gas (MIG)
Metal Active Gas (MAG)
Flux Cored (Gas Shielded)
Flux Cored (Self Shielded)
Metal Cored
* Not True Spray
Pulsed Transfer
Pulsed arc welding is a controlled method of
spray transfer, using currents lower than those
possible with the spray transfer technique, thereby
extending the applications of MIG/MAG welding
into the range of material thickness where dip
transfer is not entirely suitable. The pulsed arc
equipment effectively combines two power sources
into one integrated unit. One side of the power
source supplies a background current which
keeps the tip of the wire molten. The other side
produces pulses of a higher current that detach
and accelerate the droplets of metal into the weld
pool. The transfer frequency of these droplets is
regulated primarily by the relationship between
the two currents. Pulsed arc welding occurs
between ±50-220A, 23–35 arc volts and only with
argon and argon-based gases. It enables welding
to be carried out in all positions.
22
Dip Transfer
✓
✓
✓
✓
6.5 Fundamentals of MIG/MAG, FCAW
Welding Technique
Successful welding depends on the following
factors:
1 Selection of correct consumables
2 Selection of the correct power source
3 Selection of the correct polarity on the power
source
4 Selection of the correct shielding gas
5 Selection of the correct application techniques
a Correct angle of electrode to work
b Correct electrical stickout
c Correct travel speed
6 Selection of the welding preparation
Selection of Correct Consumable
Chemical composition
As a general rule the selection of a wire is
straightforward, in that it is only a matter of
selecting an electrode of similar composition to
the parent material. It will be found, however,
that there are certain applications that electrodes
will be selected on the basis of its mechanical
properties or level of residual hydrogen in the
Globular Transfer
✗
✓
✓
✗
and MCAW
Spray Transfer
✓
✓*
✗
✓
Advertisement
Table of Contents
