Lincoln Electric POWER MIG IM736-D Operator's Manual page 18

B-6
Arc Control (See Table B.2)
There are no specific unit values offered because the setting
of this feature largely depends upon operator preference.
Arc Control has a different effect on the character of the arc
depending upon the welding process applied.
In SMAW (STICK mode), arc control adjusts the arc force. It
can be set to the lower range for a soft and less penetrating
arc characteristic (negative numeric values) or to the higher
range (positive numeric values) for a crisp and more pene-
trating arc. Normally, when welding with cellulosic types of
electrodes (E6010, E7010, E6011), a higher energy arc is
required to maintain arc stability. This is usually indicated
when the electrode sticks to the work-piece or when the arc
pops-out during manipulative technique. For low hydrogen
types of electrodes (E7018, E8018, E9018, etc.) a softer arc
is usually desirable and the lower end of the Arc Control
suits these types of electrodes. In either case the arc con-
trol is available to increase or decrease the energy level
delivered to the arc.
In GMAW-S, the short-circuiting mode of metal transfer, the
Arc Control features the ability to increase or decrease the
energy level at the arc. Setting the arc control from 1 to 10
decreases energy, and setting the Arc Control from 0 to –10
increases the energy delivered to the arc.
Solid carbon steel electrodes in a range from .025"- .045" (.6
mm – 1.1 mm) are nominally used, and the shielding gas
blend for GMAW-S is usually 100% carbon dioxide or a
blend of argon and carbon dioxide. The Arc Control in this
scenario is set to control the droplet size and more pinch is
added (increasing pinch reduces energy to the arc) to
achieve the "bacon frying" sound associated with this mode
of metal transfer.
PROCESS
SMAW (STICK)
GMAW – S (Short
circuiting metal
transfer
GMAW – P (Pulsed
spray metal transfer)
Pulse – on –Pulse™
(Aluminum Only)
OPERATION
TABLE B.2-Arc control settings by process
ARC
CONTROL
SYNONYM
Arc Force Lower (-1 to -10) for
low hydrogen types of
electrodes. Higher (+1
to +10) for cellulosic
and other types.
Inductance or Setting -1 to -10 for
Pinch Control softer higher energy
arc. Setting +1 to +10
for a crisper lower
energy arc.
Pulsed frequency Minus settings reduces
control frequency. Plus
settings increase
frequency.
Pulsed frequency Minus settings result in
array control lower array frequency
and the plus settings
increase the array
frequency.
POWER MIG 300
Carbon steel electrodes employed in GMAW-S usually per-
form best when the droplet size is regulated by pinch to
reduce the droplet size transferred with each short-circuit
event.
When welding with solid stainless steel types of electrodes it
is usually desirable to increase the energy delivered to the
arc. High percentage argon blends with a 2 % addition of
oxygen or a three part shielding gas blend comprised of
90% Helium + 7.5% Argon + 2.5 % carbon dioxide are usu-
ally employed. The added energy is associated, in this sce-
nario, with increasing the inductance (negative numeric val-
ues). By adding to the energy level the weld bead appear-
ance improves – spatter levels decrease and wetting action
at the toes of a fillet weld increases. The arc is softer with
the higher inductance setting and the arc lends itself to
faster travel speed.
In GMAW-P, the pulsed spray mode of metal transfer, the
Arc Control is, once again, used to increase and decrease
the focus of the energy delivered to the arc. Increasing the
setting in the range of +1 to +10 results in an increase in
pulsed frequency, and the effect is to narrow the arc cone
and concentrate the available energy to a smaller area.
Decreasing the Arc Control setting from –1 to –10 results in
a reduction of pulsed frequency – the result is a broader arc
cone, which creates a wider weld bead.
Important to note here is that if a component of a pulsed
waveform is increased, then another must be decreased.
Adding pulsed frequency through an increase in the Arc
Control setting, then also results in a proportional decrease
in background current. If this were not the case, then the arc
would become too long, with too much energy, and the arc
would be unusable.
SETTING APPLICATION AND
RESULT
Minus settings are soft
and buttery for low
hydrogen electrodes.
Plus settings are harsh
and digging for other
types of electrodes.
The minus settings
result a more fluid
puddle and larger
droplet size. The lower
settings reduce the
droplet size and reduce
energy to the arc.
Wider arc cone and
weld bead. Narrower
arc cone and narrower
weld bead.
Minus settings result in
a wider bead with more
distinct ripples. Plus
settings narrow the
resultant bead and the
ripples are less distinct.
B-6