©
COPYRIGHT 1998 THE ESAB GROUP, INC. LESSON
II
gas
flows for a short interval before wire feeding starts; wire feeding starts; the
arc is initiated and
continues for a preset time (usually a few seconds). The welding current
and wire feeding stops,
and the shielding gas flows for a short interval before it automatically stops.
The process
is also useful for tacking welding pieces in position prior to running the
final weld bead.
2.4.3
EQUIPMENT
AND OPERATION
- The equipment used for gas metal arc welding
is more complicated than that required
for shielded metal arc welding. Initial cost is relatively
high, but the cost is rapidly amortized
due to the savings in labor and overhead achieved by the
rapid weld metal deposition. 2.4.3.1
The equipment necessary for gas metal
arc welding is listed below: 1) Power
source 2) Wire
feeder 3) Welding
gun 4) Shielding
gas supply 5) Solid
electrode wire 6) Protective
equipment 2.4.3.2
The basic equipment necessary for semiautomatic
gas metal arc welding is shown in
Figure 12. FIGURE
12 FLOWMETER
REGULATOR SHIELDING
GAS POWER
SOURCE GROUND
CABLE WORK
WELDING GUN WELD
CABLE 115V
CONTACTOR
MAGNETIC VALVE
TRIGGER CONTROL
LEAD FEED ROLLS
GAS HOSE WIRE
FEEDER WIRE SPOOL
+ _
SCHEMATIC DIAGRAM SEMI-AUTOMATIC GMAW
EQUIPMENT
