Rival TIG 185 DC Operating Manual - page 6
EN
TIG 185 DC. Operating manual.
TIG 185 DC. Operating manual.
11
10
2.5 Consumable selection
Filling rod
Filler rod diameter (mm)
Thickness of metal (mm)
2
3
4
4 or 5
5 or 6
0.5–2
2–5
5–8
8–12
12 or more
2.6 Non-consumable tungstens – tungsten electrode selector chart
Copper alloys, Cu-NI alloys and nickel alloys
Thickness range
All
Only thin sections
Only thick sections
Desired results
General purpose
Control penetration
Increase penetration
or travel speed
Welding
current
DCSP
ACHF
DCSP
Electrode type
2% Thoriated
(EW-Th2)
2% Ceriated
(EW-Ce2)
Zirconiated
(EW-Zr)
2% Ceriated
(EW-Ce2)
Shielding gas
75% Argon/
25% Helium
75% Argon/
25% Helium
Argon
75% Argon/
25% Helium
Tungsten performance characteristics
Best stability at medium currents. Good arc starts.
Medium tendency to spit. Medium erosion rate.
Low erosion rate. Wide current range. AC or DC.
No spitting. Consistent arc starts. Good stability.
Use on lower currents only. Spitting on starts.
Rapid erosion rates at higher currents.
Low erosion rate. Wide current range. AC or DC.
No spitting. Consistent arc starts. Good stability.
Mild steels, carbon steels, alloy steels, stainless steels and titanium alloys
Thickness range
All
Only thin sections
Only thick sections
Desired results
General
purpose
Control penetration
Increase penetration
or travel speed
Welding
current
DCSP
ACHF
DCSP
Electrode type
2% Thoriated
(EW-Th2)
2% Ceriated
(EW-Ce2)
2%
Lanthanated
(EWG-La2)
Zirconiated
(EW-Zr)
2% Ceriated
(EW-Ce2)
2%
Lanthanated
(EWG-La2)
Shielding gas
75% Argon/
25% Helium
75% Argon/
25% Helium
75% Argon/
25% Helium
Argon
75% Argon/
25% Helium
Helium
Tungsten performance characteristics
Best stability at medium currents. Good arc starts.
Medium tendency to spit. Medium erosion rate.
Low erosion rate. Wide current range. AC or DC.
No spitting. Consistent arc starts. Good stability.
Lowest erosion rate. Widest current range on DC.
No spitting. Best DC arc starts and stability.
Use on lower current only. Spitting on starts.
Rapid erosion rates at higher currents.
Low erosion rate. Wide current range. No spitting.
Consistent arc starts. Good stability.
Lowest erosion rate. Highest current range.
No spitting. Best DC arc starts and stability.
3. Manual Metal Arc Welding (MMAW).
reversal is called a ‘half cycle’ and repeats as long as the current
flows. The rate of change of direction of current flow is known as the
‘frequency’ of the supply and is measured by the number of cycles
completed per second.
3.3 Welding machine
Basic welding machine and cables
The choice of welding machine is based mostly on the following factors:
→ primary voltage, e.g. 240 volt or 380 volt
→ output amperage required, e.g. 140 amps
→ output required, e.g. AC or DC +/-
→ duty cycle required, e.g. 35% @ 140 amps
→ method of cooling, e.g. air-cooled or oil-cooled method of output
amperage control, e.g. tapped secondary lugs
→ infinitely variable control
Having decided on a welding machine, appropriate accessories are
required. These are items such as welding cables, clamps, electrode
holder, chipping hammer, helmet, shaded and clear lenses, skull cap,
gloves and other personal protective equipment.
3.1 Introduction
The main purpose of this manual is to help the welder with limited
experience to obtain a better understanding of the process, and to
acquire a reasonable degree of proficiency in the least possible time.
Even welders with experience may benefit from the information in this
manual.
3.2 Process
Manual Metal Arc welding is the process of joining metals where an
electric arc is struck between the metal to be welded (parent metal) and
a flux-coated filler wire (the electrode). The heat of the arc melts the
parent metal and the electrode which mix together to form, on cooling, a
continuous solid mass.
Before arc welding can be carried out, a suitable power source is
required. Two types of power sources may be used for arc welding, direct
current (DC) or alternating current (AC).
1
Weld metal,
2
Slag,
3
Flux covering,
4
Core wire,
5
Arc,
6
Weld pool,
7
Workpiece
1
2
3
4
5
6
7
The essential difference between these two power sources is that, in the
case of DC, the current remains constant in magnitude and flows in the
same direction. Similarly, the voltage in the circuit remains constant in
magnitude and polarity (i.e. positive or negative).
In the case of AC however, the current flows first in one direction and
then the other. Similarly, the voltage in the circuit changes from positive
to negative with changes in direction of current flow. This complete