Selco Genesis 282 Instrucciones De Uso página 22

Steel TIG welding
The TIG procedure is very effective for welding both carbon and
alloyed steel, for first runs on pipes and for welding where good
appearance is important.
Straight polarity is required (D.C.S.P .).
Preparing the edges
An accurate cleaning and preparation of the edges are required.
Choosing and preparing the electrode
The use of thorium-tungsten electrodes (2% thorium-red colour)
with the diameters indicated below is recommended:
Ø electrode (mm)
1.0
1.6
2.4
3.2
The electrode must be pointed as indicated in Fig.11.
(°)
30
60÷90
90÷120
Filler material
The filler rods must have mechanical characteristics com-
parable to those of the base material.
Do not use straps obtained from the base material, since they
may contain working impurities that can negatively affect the
quality of the welding.
Protective gas
Practically, pure argon (99.99%) is always used.
Welding Ø Electrode
current (A) (mm)
6-80 1.0
70-150 1.6
150-250 2.4
250-400 3.2
Copper TIG welding
Since the TIG welding is a process characterized by high heat
concentration, it is particularly suitable for welding materials
with high thermal conductivity, like copper.
For TIG welding of copper, follow the same directions as for TIG
welding of steel or specific instructions.
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Current range (A)
6÷80
70÷150
150÷250
250÷400
Fig.11
current range (A)
0÷30
30÷120
120÷250
Gas nozzle Argon flow
n° Ø (mm) (l/min)
4/5 6/8.0 5-6
4/5/6 6.5/8.0/9.5 6-8
6/7 9.5/11.0 7-10
7/8/9 11/12.5/14 10-15