Welding Defects - Cebora EVO 200 M Manual De Instrucciones

PROTECTION. (only for Arts. 622, 624 and 625).
Make sure that the cables are properly inserted on the
terminal board, so that the poles match correctly (see
figure 5).
To attain well connected and protected welds, always
work from left to right and top to bottom. Remove all
waste at the end of each welding session.
The flux-cored wire to be used is our Art. 1587, Ø 0.9mm.
5.4 WELDING CARBON STEELS WITH GAS
PROTECTION.
Make sure that the cables are properly inserted on the
terminal board, so that the poles match correctly (only for
Art. 622, 624 and 625, see figure 5).
In order to weld these materials you must:
• Use a welding gas with a binary composition, usually
ARGON + CO2 with percentages of Argon ranging from
75% up. With this blend, the welding bead will be well
jointed and attractive.
Using pure CO2 as a protection gas will produce narrow
beads, with greater penetration but a considerably
increase in splatters.
• Use a welding wire of the same quality as the steel to
be welded. It is best to always use good quality wires,
avoiding welding with rusted wires that could cause

welding defects.

• Avoid welding rusted parts, or those with oil or grease
stains.
5.5 WELDING STAINLESS STEEL
Make sure that the cables are properly inserted on the
terminal board, so that the poles match correctly (only for
Art. 622, 624 and 625, see figure 5 ).
Series 300 stainless steels must be welded using a
protection gas with a high Argon content, containing a small percentage of O2 or carbon dioxide CO2
(approximately 2%) to stabilize the arc.
Do not touch the wire with your hands. It is important
to keep the welding area clean at all times, to avoid
contaminating the joint to be welded.
5.6 WELDING ALUMINUM
14
Fig. 5
Make sure that the cables are properly inserted on the
terminal board, so that the poles match correctly (only for
Art. 622, 624 and 625, see figure 5).
In order to weld aluminum you must use:
• Pure Argon as the protection gas.
• A welding wire with a composition suitable for the base
material to be welded.
• Use mills and brushing machines specifically designed
for aluminum, and never use them for other materials.
• In order to weld aluminum you must use the torches:
PULL 2003 Art. 2003 or SPOOL-GUN Art. 1562 with the
connection Art. 1196 (only for Art. 622, 627 and 641).
NOTE: If only a torch prepared for steel wires is available,
it must be altered as follows:
• Make sure that the cable is no more than 3 meters long.
• Remove the brass liner nut, gas nozzle, contact tip, and
then slip off the liner.
• Insert our liner Art. 1929, making sure that it protrudes
from both ends.
• Screw the contact tip back on so that the liner adheres
to it.
• In the free end of the liner, insert the liner nipple and
O-ring, and fasten with the nut without over-tightening.
• Insert the brass tube on the liner and insert the entire
unit in the adapter, after first removing the iron sleeve.
• Cut the liner diagonally so that it is as close as possible
to the wire feeder roller.
• Use wire feeder rollers suitable for aluminum wire.
• Adjust the pressure exerted by the arm of the wire feeder
group on the roller, to the lowest possible setting.
6 WELDING DEFECTS
1 DEFECT- Porosity (within or outside the bead)
CAUSES • Electrode defective (rusted surface)
• Missing shielding gas due to:
- low gas flow
- flow gauge defective
- regulator frosted due to no preheating of
the CO2 protection gas
- defective solenoid valve
- contact tip clogged with spatter
- gas outlet holes clogged
- air drafts in welding area.
2 DEFECT - Shrinkage cracks CAUSES • Wire or workpiece dirty or rusted.
• Bead too small.
• Bead too concave.
• Bead too deeply penetrated.
3 DEFECT - Side cuts CAUSES • Welding pass done too quickly
• Low current and high arc voltages.
4 DEFECT - Excessive spraying
CAUSES • Voltage too high.
• Insufficient inductance.
• No preheating of the CO2 protection gas.
7 MAINTENANCE