Mig-Mag Welding - Telwin INVERPULSE 625 MIG Manual De Instrucciones

of the torch head.
4- Tighten up the hose locking nut by hand.
5- Trim off all the excess protruding hose pressing it slightly; remove it from the torch
cable again.
6- Smooth the part where the hose was cut and reinsert it into the cable-torch duct.
7- Tighten up the nut again using a spanner.
8- Reassemble the contact tip and nozzle.
5.7.2 Synthetic hose for aluminium wires
Carry out operations 1, 2, 3 as given for the steel hose (ignore operations 4, 5, 6, 7, 8).
9- Re-tighten the contact tip for aluminium, making sure it comes into contact with the
hose.
10- At the other end of the hose (torch connector end) insert the brass nipple and the
OR ring and, keeping slight pressure on the hose, tighten the hose locking nut.
The excess part of the hose will be removed to size later on (see (13)).
Extract the capillary pipe for steel hoses from the wire feeder torch connector.
11- THE CAPILLARY PIPE IS NOT REQUIRED for aluminium hoses of diameter 1.6-
2.4mm (coloured yellow); the hose is therefore inserted into the torch connector
without it.
Cut the capillary pipe for aluminium hoses of diameter 1-1.2mm (coloured red) to
approx. 2mm shorter than the steel pipe, and insert it into the free end of the hose.
12- Insert and lock the torch into the wire feeder connector, mark the hose at 1-2mm
from the rollers, take the torch out again.
13- Cut the hose to the required size, without distorting the inlet hole.
Reassemble the torch in the wire feeder connector and assemble the gas nozzle.
6. WELDING: DESCRIPTION OF THE PROCEDURE
6.1 MIG-MAG WELDING
6.1.1 SHORT ARC TRANSFER MODE
The melting of the electrode wire and the detachment of the drop is produced by
repeated short circuits (up to 200 times per second) from the tip of the wire to the
molten pool.
Carbon and mild steels
- Suitable wire diameter:
- Welding current range:
- Arc voltage range:
- Suitable gases:
Stainless steels
- Suitable wire diameter:
- Welding current range:
- Arc voltage range:
- Suitable gases:
Aluminium and alloys
- Suitable wire diameter:
- Welding current range:
- Arc voltage range:
- Suitable gases:
Generally, the contact tip should be flush with the nozzle or protrude slightly when
using the thinnest wires and lowest arc voltages; the length of free wire (stick-out) will
normally be between 5 and 12mm.
In MANUAL MODE ("PRG 0") adjust the reactance value:
- 5%-60% with carbon steel wires of diameter 0.8-1mm.
- 50%-80% with carbon steel wires of diameter 1.2-1.6mm.
- 0%-80% with stainless steel and aluminium wires.
Application: Welding in all positions, on thin material or for the first passage in
bevelled edges, with the advantage of limited heat transfer and highly controllable
pool.
Note: SHORT ARC transfer for welding aluminium and alloys should be used with
great care (especially with wires of diameter >1mm) because the risk of melting
defects may arise.
6.1.1.1 ROOT MIG TRANSFER MODE
ROOT MIG is a particular type of MIG Short Arc welding technique studied to keep the
weld pool colder than the Short Arc itself. Thanks to the very low heat transfer, welding
material can be deposited and only a minimum part of the piece being processed
deforms.
ROOT MIG is therefore ideal for manually filling splits and cracks. In addition the filling
operation, with regard to TIG welding, does not need welding material and it is easier
and faster to carry out.
The ROOT MIG programs are dedicated to processing carbon steel and low-alloy
steel (see TAB. 3).
6.1.2 SPRAY ARC TRANSFER MODE
Higher voltages and currents than for "short arc" are used here to achieve the melting
of the wire. The wire tip does not come into contact with the molten pool; an arc forms
from the tip and through it flows a stream of metallic droplets. These are produeced by
the continuous melting of the electrode wire without short-circuits involved.
Carbon and mild steels
- Suitable wire diameter:
- Welding current range:
- Arc voltage range:
- Suitable gases:
Stainless steels
- Suitable wire diameter:
- Welding current range:
- Welding voltage range:
- Suitable gases:
Aluminium and alloys
- Suitable wire diameter:
- Welding current range:
- welding voltage range:
- suitable gases:
The contact tip should generally be 5-10mm inside the nozzle, the higher the arc
voltage the further inside; the length of free wire (stick-out) should normally be
between 10 and 12mm.
Application: Horizontal welding with thicknesses of at least 3-4mm (very fluid pool);
execution rate and deposit rate are very high (high heat transfer).
6.1.2.1 TRANSFERRING TO THE DEEP MIG MODE
DEEP MIG is an advanced MIG Spray Arc welding arc that gives a hotter and deeper
weld pool than the traditional Spray Arc method. During welding, the machine adjusts
a constant arc length that guarantees a regular energy supply, even if the distance
between the welding torch and the workpiece varies.
This process is recommended for welding pieces that are more than 2 mm thick,
because the notable heat transfer prevents some welding faults that appear more
easily using a normal Spray Arc.
The most evident advantages when using the DEEP MIG mode are:
- Lower risk of the material not melting.
- Less need to adjust the welding parameters.
- Easy to use in production processes.
- Lower reworking costs because of lower welding faults.
- Suitable for use with long or short cable sets.
The DEEP MIG programs are specific for working carbon steel, low-alloy steel and
stainless steel (see TAB. 3).
6.1.3 PULSE ARC TRANSFER MODE
This is a "controlled" transfer situated in the "spray arc" transfer area (modified spray
arc) and therefore has the advantages of speedy melting and lack of projections,
extending to significantly low current values so as to satisfy many typical "short arc"
applications as well.
Every current impulse corresponds to the separation of a single drop from the wire
electrode; the phenomenon occurs with a frequency that is proportional to the wire
feed rate with the variation rule related to the type and diameter of the wire itself
(typical frequency values: 30-300Hz).
Carbon and mild steels
- Suitable wire diameter:
- Welding current range:
- Arc voltage range:
- Suitable gases:
Stainless steels
- Suitable wire diameter:
- Welding current range:
- Welding voltage range:
0.6-1.2mm - Suitable gases:
Aluminium and alloys
40-210A
14-23V - Suitable wire diameter:
, mix Ar/CO , Ar/CO /O - Welding current range:
CO
2 2 2 2
- welding voltage range:
0.8-1mm - suitable gases:
40-160A
14-20V Normally the contact pipe should be 5-10mm inside the nozzle, the higher the arc
mix Ar/O , Ar/CO (1-2%) voltage, the further inside; the length of free wire (stick-out) will normally be between
2 2
10 and 12mm.
0.8-1.6mm
75-160A Application: "horizontal" welding on medium-low thicknesses and on heat-sensitive
16-22V materials, particularly suitable for welding light alloys (aluminium and its alloys)
Ar 99.9% also on thicknesses below 3mm.
6.1.4 ADJUSTING THE WELDING PARAMETERS IN MIG-MAG
6.1.4.1 Protective gas
The gas flow rate should be:
short arc: 8-14 l/min
spray arc and pulse arc: 12-20 l/min
depending on welding current intensity and nozzle diameter.
6.1.4.2 Welding current
Welding current is adjusted by the operator by turning the encoder knob (FIG. D
(14)). When SPRAY/SHORT ARC is selected, each turn of the encoder knob (14)
corresponds to a wire feed rate adjustment (m/minute), which is shown on the display
(16); during welding, the display automatically switches to the actual current value
(amps).
When PULSE ARC or PULSE ARC PULSE-ON-PULSE is selected, each time the
encoder knob (14) is turned this corresponds to an adjustment of welding current,
which is shown on the display (16); during welding, the display automatically switches
to the actual current value.
In both modes it is possible to press key (17) to pass to regulation of thickness in mm
(LED (16b) lit up) using the encoder (14). The machine automatically calculates the
current required to weld this thickness. Also in this case the display will switch to the
actual current (amps.) during welding.
It should be pointed out that in all the synergic programs the maximum and minimum
values for the settings (m/minute, amps or thickness in mm) are programmed in the
factory and cannot be changed by the user.
Indicative values for the current with the most commonly used wires are given in the
table (TAB. 4).
6.1.4.3 Arc voltage and Pinch-off
In MIG-MAG pulse-arc and pulse-on-pulse synergy programs (10d) these two
parameters determine the dimension of the arc during welding
The arc voltage indicates the distance of the wire from the piece. The discretion margin
of the operator is limited to the simple correction from -5% to +5% of the voltage value
that is preset in each program to adapt the effective length of the arc for specific needs
if necessary. The higher the value the farther the wire from the piece.
0.8-1.6mm In the "PRG 0" manual program the arc voltage is defined by setting a suitable value
180-450A for the wire feed rate, selected using the formula
24-40V U
, Ar/CO /O - U
mix Ar/CO
2 2 2
- I
1-1.6mm It must be considered that the loaded voltage (during welding) is to 2-4V less than the
140-390A selected loadless voltage value.
22-32V The pinch-off instead determines the arc concentration or width; the correction range
mix Ar/O , Ar/CO (1-2%) of this parameter goes from -10% to +10% of the program default value. The higher
2 2
the value, the more concentrated the arc will be.
0.8-1.6mm
120-360A 6.1.5 BI-LEVEL AND PULSE ON PULSE OPERATION
24-30V Bi-level operation: Set using key (FIG. D (8)) and can be selected in MIG-MAG pulse
Ar 99.9% arc and short arc modes. The welding cycle begins by pressing and releasing the
torch pushbutton (like the 4-stroke), the initial work point of the welding machine is
equal to the main welding level (FIG. D (LED (10a)) and the machine shows current
and voltage of this work point. Keeping the torch pushbutton pressed for less than 0.5
seconds makes the machine change the work point from the main to the secondary
level (FIG. D (LED (10b)), showing the secondary level current and voltage on the
display. With each subsequent push of the torch pushbutton, the machine continues
passing from one level to another until the pushbutton is kept pressed for longer than
0.5 seconds, starting the down slope of the current thus ending the welding.
During welding, and even if the machine shows the immediate current and voltage
values, only the arc current and voltage of the main welding level can be varied.
MIG-MAG Pulse on Pulse operation: can be activated using key (FIG. D (7))
together with the MIG-MAG Pulse arc LED. This is a special type of bi-level mode
- 10 -
= ( 14+0,05 I ) where:
2 2
= Arc voltage in volts.
2
= Welding current in amperes
2
0.8-1.6mm
60-360A
18-32V
, Ar/CO /O (Co max 20%)
mix Ar/CO
2 2 2 2
0.8-1.2mm
50-230A
17-26V
mix Ar/O , Ar/CO (1-2%)
2 2
0.8-1.6mm
40-320A
17-28V
Ar 99.9%