Table of Contents
Advertisement
3.0 TIG welding of materials
3.1
Application summary
Material
C-Mn steel
Alloyed steel
Copper and Cu alloys
Nickel and Ni alloys
Titanium and Ti alloys
Aluminum and Al alloys
Magesium and Mg alloys
C-Mn steel welding parameters
Plate thickness (mm)
Joint type
Number of passes
Tungsten electrode (mm)
Consumable size (mm)
Current (A)
Welding speed (cm/min)
Gasflow (l/min)
Shielding gas: Argon, Consumable ER70S-6, Position: Downhand, Polarity: DC–
Type of current
Polarity
Direct current (-)
DC negative
Direct current (-)
DC negative
Direct current (-)
DC negative
Direct current (-)
DC negative
Direct current (-)
DC negative
Alternating current (~)
Direct current (-)
DC negative
with Helium
Alternating current (~)
0.8
Fillet
1
1.6
1.6
70
30
5
3.2
C-Mn steel
TIG welding may be used for welding carbon steel but because
deposition rates are low, it is usually only used for welding sheet and
thin sections for high quality applications, small components, and root
passes of multipass butt joints in plate and pipe.
Standard DC TIG equipment is normally suitable and DCEN polarity is
usually chosen to provide good workpiece heating.
Only inert or reducing gases should be used for TIG welding and pure
argon is normally recommended as the shielding gas for steel.
Filler rods are usually selected to match the chemical composition and
the mechanical properties of the parent plate. The weldability of the
steel may impose restrictions on the choice of filler rod.
Steels with carbon contents above about 0.3% are hardenable, and fast
cooling will produce a hard HAZ and this is liable to result in hydrogen
cracking. This form of cracking can be prevented by use of preheat and
suitable welding procedures.
1
1.5
2
Fillet
Fillet
Fillet
1
1
1
1.6
1.6
2.4
1.6
2
2.4
90
110
130
30
30
25
5
6
6
BOC Smootharc TIG 200 DC Operating Manual
1
1.5
Butt
Butt
1
1
1.6
1.6
1.6
2
80
120
20
20
6
7
17
2
Butt
1
2.4
2.4
140
20
7
Advertisement
Table of Contents
