Coated Electrode Welding - Telwin HF Serie Manual De Instrucciones

For greater thicknesses it is necessary to use filler rods of
the same composition as the basic material. These must be
of a suitable diameter, with the edges properly prepared.
Welding with turned edges with or without filler rod
For a good weld it is important for the workpieces to be
accurately cleaned, with no oxides, oil, grease, solvents, etc.
remaining on the surface.
It is necessary to sharpen the tungsten electrode axially on
the grinder wheel as indicated below. Make sure that the tip
is perfectly concentric in order to avoid arc deviations. This
operation should be repeated periodically according to the
usage and wear, or if the electrode is accidentally
contaminated, oxidated or incorrectly used.
Check of the electrode tip Fig. I
The diameter of the electrode is to be chosen according to
the following tables taking into account that for the DC
welding (electrode negative), 2% Ce electrode is generally
used.
In order to produce a good weld it is most important that the
proper electrode diameter is used with the corresponding
current. The normal stick-out of the electrode from the
ceramic nozzle is 2-3 mm and can reach up to 8mm for
corner welding.
PROCEDURE
Check that the machine is correctly connected and installed
according to the instructions indicated in the paragraph
"Installation".
Check the the comands are set in the correct position
according to General Rules.
Set the welding current to the required value using the
potentiometer. If necessary, adjust during welding to the
correct thermic value.
Push the torch trigger, checking the gas flow from the
nozzle.
N.B.: The quantity of protection gas (litres/minute) can
only be adjusted by the pressure regulator of the
cylinder.
HF MODEL :
Press the torch pushbutton bringing the electrode tip close
to the workpiece (2-3 mm). Wait for the striking of the arc
transferred by HF impulses and when this occurs, form the
molten pool on the workpiece and proceed along the joint.
When it is difficult to strike the arc despite the presence of
gas and the visible HF disharges, do not leave for long the
electrode under HF. Check the integrity of the electrode
surface and the shape of its tip and grind it if necessary.
WARNING! Always turn off the gas cylinder valve at the
end of the work.
WELDING PARAMETERS FOR WELDING ON
STAINLESS STEEL (DC)
ThicknessCurrent Electrode
(mm) (A) (mm)
0,5-0,8 15-30 1
1 30-60 1
1,5 70-100 1,6
2 90-110 1,6
2,5 110-130 1,6
3 120-150 1,6-2,4
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Fig. H
Nozzle Argon ø Filler rod
ø ø
(mm) (I/min) (mm)
6,5 3 ---
6,5 3-4 1
9,5 3-4 1,5
9,5 4 1,5-2,0
9,5 5 1,5-2,0
9,5 5-6 2-3
WELDING PARAMETERS FOR DEOXIDATED COPPER
Thickness Current ø Electrode
(mm) (A)
0,5 - 0,8 20-30
1 80-100
1,5 110-140

COATED ELECTRODE WELDING

- Most stick electrodes are connected to the positive pole,
although certain types must be connected to the
negative pole, connect according to either type to the
(+) or (-) quick plugs.
- It is most important that the user refers to the maker's
instructions indicated on the stick electrode packaging.
This will indicate the correct polarity of the stick
electrode and the most suitable current.
- The welding current must be regulated according to the
diameter of the electrode in use and the type of the joint
to be carried out: see below the currents
corresponding to various electrode diameters:
ø Electrode (mm)
1.6
2
2.5
3.2
4
- The user must consider that, according to the electrode
diameter, higher current values must be used for flat
welding, whereas for vertical or overhead welds lower
current values are necessary.
- The mechanical character of the weld will be determined
not only by the current intensity used, but also by other
parameters such as the diameter and quality of the
electrode, the arc length , the speed and position of the
user. It will also depend on the state of the electrodes in
use, which should be protected from damp by their
packaging.
WELDING PROCEDURE
- Holding the mask IN FRONT OF THE FACE, strike the
electrode tip on the workpiece as if you were striking a
match. This is the correct strike-up method.
WARNING: do not hit the electrode on the workpiece,
this could damage the electrode and make strike-up
difficult.
- As soon as arc is ignited, try to maintain a distance from
the workpiece equal to the diameter of the electrode in
use. Keep this distance as much constant as possible
for the duration of the weld. Remember that the angle of
the electrode as it advances should be of 20-30 grades.
- At the end of the weld bead, bring the end of the
electrode backward, in order to fill the weld crater,
quickly lift the electrode from the weld pool to extinguish
the arc.
CHARACTERISTICS OF THE WELD BEAD
MAINTENANCE
WARNING!
NEVER REMOVE PANELS OR OPERATE WITHIN THE
UNIT WITHOUT DISCONNECTING THE MAINS POWER
SUPPLY . CHECKING OPERATIONS WHEN THE UNIT IS
UNDER VOLTAGE MAY CAUSE SERIOUS ELECTRIC
14
ø Nozzle Argonø
(mm) (mm) (I/min)
1 6,5 4
1,6 9,5 6
1,6 9,5 6
Welding current (A)
Min. Max.
25 - 50
40 - 80
60 - 110
80 - 160
120 - 200
Fig. L
Filler rod
(mm)
---
1,5
1,5