Tig Welding; Description - Praxair MICROTIG 161 Instrucciones De Utilizacion

2. TIG WELDING (Tungsten inert gas)
It is a process of arc welding under shield gas, using a torch
with infusible tungsten electrode and which can be run with
or without filler metal in an inert gas atmosphere such as argon
and mixtures thereof. Through this process the arc become mo-
re stable without spatter which guarantees a strong mechanical
resistance of the welding joint.
This Tig process replaces with many advantages the oxyacetylene
aluminum on AC welding and, in several cases, the MMA and
Mig welding especially when the welding seam remains visible.
Electrode chemical composition
Code
WP
WT4
WT10
WT20
WT30
WT40
WZ3
WZ8
WL10
WC20
∅ Electrode
(mm)
1,6 mm
2,0 mm
2,5 mm
3,2 mm
4,0 mm
5,0 mm
Shield gas: The shield gas is used to:
- Involve the welding arc on an ionisable atmosphere.
- Avoid the seam contamination by the oxygen of the atmosphere.
- Provide the cooling of the electrode.
Argon (Ar) – Is the most common gas used with a purity grade of 99,9%.
Helium (He) – For the copper welding mixed with the argon under percentages between 10% and 75%.
Hydrogen (H) – Inert gas at environment temperature especially for the use on copper welding. Inadvisable for welding on
closed places; it mixes with the atmosphere oxygen and changes the air unbreathable.

3 - DESCRIPTION

This machine makes part of an inverter generation, using the electronic IGBT technology, which allows:
- A considerable reduction of weight and dimensions
- Dynamic control and current welding regulation
- Internal protection of electronic components
- Great power in reduced dimensions low energy consumption.
Composition Type
Pure tungsten
0,35-0,55% thorium
0,80-1,20% thorium
1,7-2,3% thorium
2,7-3,3% thorium Th
3,8-4,3% thorium
0,15-0,50% zirconium
0,70-0,10% zirconium
1,0-1,2% lanthanum La
1,9-2,3% cerium Ce
Chart of electrode diameter and current
Amp. DC
Negative (-)
40-130 A
75-180 A
130-230 A
160-310 A
275-450 A
400-625 A
on steel, stainless steel, copper, brass DC welding, the a-
Color
W Green AC – Aluminum, Magnesium
Blue
DC
Yellow
Steel, Stainless steel, Titanium,
Red
Copper
Violet
Orange
Brown
Stainless steel, Nickel, Non ferric
Zr
White metals
Black All TIG applications
Grey All TIG applications
Positive (+)
10-20 A
15-25 A
17-30 A
20-35 A
35-50 A
50-70 A
Welding
Amp. AC
45-90 A
65-125 A
80-140 A
150-190 A
180-260 A
240-350 A
5