Tig Welding - Welbach AMPERO 225 Manuel D'utilisation

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When choosing the electrode for a performed task, the attention should be paid to:
• Welded material grade
• Welded material thickness
• Type of work (welding, padding)
• Welding position
Recommended electrodes shielded
Popular steel electrodes
AWS class Item Polarity Application
E6011 All AC Universal shielded cellulose electrode used to weld coal steel and
DC- galvanised steel; tensile strength 60,000 PSI, deep weld penetration.
DC+ It is ideal when precise removal of soiling, rust or paint layers is not
possible.
E6013 All AC Universal rutile shielded electrode with high welding properties and
DCEN universal application. Low or medium weld penetration -
DCEP depending on the diameter, it allows to weld thin materials; it is
designed to use with coal steel; 60,000 PSI tensile strength. Welding
ease and striking the arc makes it perfect for inexperienced
welders with lower qualifications as well as with incorrectly chosen
materials. It can match with devices of low off-load voltage.
E7014 All AC Rutile-low hydrogen electrode thickly shielded. Tensile strength ca.
DCEN 70.000 PSI. Ideal for applications for which high welding speed and
DCEP deep weld penetration is required. Used for welding steel construc-
tions statically and dynamically loaded (ship constructions, building
machines, railway rolling stock.
E7018 All AC Low-hydrogen electrode for medium and high-carbon steels. Tensile
DCEN strength ca. 70.000 PSI. Idea for welding in places with difficult ac-
DCEP cess. Not recommended for AC low voltage welding. Recommended
for welding of structures susceptible to high static
and dynamic loads. Ensures smooth and clean welds with smooth
connection with the parent material. It is characterised with a calm
and stable arc with low chipping rate.
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1. welding direction
9 2. shielded electrode
3. shielding gas generated on burning the
electrode coating
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4. electrical arc
5. welded material
6. weld
7. solidified slag
8. liquid slag
9. weld pool
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E7018AC All AC This electrode has the same properties as E7018, but has been
DCEN improved - operation with alternating current.
DCEP
Special welding shielded electrodes
308L stain- All AC For welded material with the following symbols: 301, 302, 304, 305,
less steel DCEP 308; Electrode
in rutile coating for welding of austenitic stainless steels Cr-Ni
with very low carbon content as well as for welding of chromium
plated or heat resistant stainless steels and cast steels. Max. opera-
ting temp. of the filler metal up to +350 °C
Stainless All AC/DC Electrode in rutile coating for welding of opposite polarity steels as
steel well as for plating of ferritic steels. The filling metal is characterised
312 Plus with high crack resistance. Electrode suitable for steels difficult to
weld and to apply buffer de-stressing layers on parent metals suscep-
tible to breaking. Suitable for welding of galvanised steel plates.
DCEN = DC electrode negative (minus on electrode, plus on earth lead) DCEP = DC electrode positive
(plus on electrode, minus on earth lead)

5.3 TIG welding

TIG welding devices are divided into devices for direct current welding (TIG DC) and alternating current
welding (TIG AC). In practice, the TIG AC welders also support the TGI DC mode, therefore they are referred
to as TIG AC/DC welders. In DC mode, they allow to weld steel, stainless steel, certain colour metals with
direct current, whereas in AC mode - aluminium can be welded using alternating current. All TIG devices allow
for MMA method welding, upon connection of proper cables. To facilitate welding of thin materials (introduce
less heat to the material), the pulse function is used. The pulse parameters include: impulse current, base current,
impulse frequency and impulse filling.
A tungsten non-consumable electrode is necessary for welding. It is available with diameters of 1, 1,6, 2, 2,4, 3.2, 4
mm and with various tip colours, depending on the raw material composition and, thus, intended application. The
most popular colours are red - for steel and acid resistant steel, and red - for aluminium. The standard electrode
length is 175 mm.
5.3.1 Positions of the TIG torch for different types of welds
• TIG method butt joint
When making a butt joint, the weld must be guided along the material contact. The material must be prepared
acc. to general principles. Depending on the material thickness, a single- or multi-layer weld must be made.
• Double-lap connection
In order to make a double-lap joint, form the welding puddle in such a manner as to obtain a weld as shown in
the figure below. Remember that the edge of the western part melts faster, so the filler metal must be added
close to its edge.
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