Tig Welding; Typical Current Ranges For Tungsten Electrodes - Lincoln Electric VANTAGE 500-I Operator's Manual

B-7

TIG WELDING

The TOUCH START TIG setting of the MODE switch
is for DC TIG (Tungsten Inert Gas) welding. To initiate
a weld, the OUTPUT CONTROL dial is first set to the
desired current and the tungsten is touched to the
work. During the time the tungsten is touching the
work there is very little voltage or current and, in gen-
eral, no tungsten contamination. Then, the tungsten is
gently lifted off the work in a rocking motion, which
establishes the arc.
When in the TOUCH START TIG mode and when a
Amptrol is connected to the 6-Pin connector the OUT-
PUT CONTROL dial is used to set the maximum cur-
rent range of the current control of the Amptrol.
The ARC CONTROL is not active in the TIG mode. To
STOP a weld, simply pull the TIG torch away from the
work.
When the arc voltage reaches approximately 30 Volts
the arc will go out and the machine will reset the cur-
rent to the Touch Start level.
To reinitiate the arc, retouch the tungsten to the work
and lift. Alternatively, the weld can be stopped by
releasing the Amptrol or arc start switch.
TYPICAL CURRENT RANGES
Tungsten Electrode DCEN (-)
Diameter in. (mm)
1%, 2% Thoriated
Tungsten
.010 (.25) 2-15
0.020 (.50) 5-20
0.040 (1.0) 15-80
1/16 (1.6) 70-150
3/32 (2.4) 150-250
1/8 (3.2) 250-400
5/32 (4.0) 400-500
3/16 (4.8) 500-750
1/4 (6.4) 750-1000
(1) When used with argon gas. The current ranges shown must be reduced when using argon/helium or pure helium shielding gases.
(2) Tungsten electrodes are classified as follows by the American Welding Society (AWS):
Pure
1% Thoriated
2% Thoriated
Though not yet recognized by the AWS, Ceriated Tungsten is now widely accepted as a substitute for 2% Thoriated Tungsten in AC and DC applications.
(3) DCEP is not commonly used in these sizes.
(4) TIG torch nozzle "sizes" are in multiples of 1/16ths of an inch:
# 4 = 1/4 in. (6 mm)
# 5 = 5/16 in. (8 mm)
# 6 = 3/8 in. (10 mm)
# 7 = 7/16 in. (11 mm)
# 8 = _ in. (12.5 mm)
#10 = 5/8 in. (16 mm)
(5) TIG torch nozzles are typically made from alumina ceramic. Special applications may require lava nozzles, which are less prone to breakage, but cannot withstand high temperatures
OPERATION
TABLE B.3
FOR TUNGSTEN ELECTRODES
(1)
DCEP (+) Approximate Argon Gas Flow
Flow Rate C.F.H. ( l /min.)
1%, 2% Thoriated Aluminum
Tungsten
(3) 3-8 (2-4)
(3) 5-10 (3-5)
(3) 5-10 (3-5)
10-20 5-10 (3-5)
15-30 13-17 (6-8)
25-40 15-23 (7-11)
40-55 21-25 (10-12)
55-80 23-27 (11-13)
80-125 28-32 (13-15)
EWP
EWTh-1
EWTh-2
VANTAGE® 500-I
The VANTAGE® 500-I can be used in a wide variety
of DC TIG welding applications. In general the 'Touch
Start' feature allows contamination free starting with-
out the use of a Hi-frequency unit. If desired, the
K930-2 TIG Module can be used with the VANTAGE®
500-I. The settings are for reference.
VANTAGE® 500-I settings when using the K930-2
TIG Module with an Amptrol or Arc Start Switch:
• Set the MODE Switch to the TOUCH START TIG
setting.
• Set the "IDLER" Switch to the "AUTO" position.
• Set the "WELDING TERMINALS" switch to the
"REMOTELY CONTROLLED" position. This will
keep the "Solid State" contactor open and provide a
"cold" electrode until the Amptrol or Arc Start
Switch is pressed.
When using the TIG Module, the OUTPUT CONTROL
on the VANTAGE® 500-I is used to set the maximum
range of the CURRENT CONTROL on the TIG
Module or an Amptrol if connected to the TIG Module.
Nozzle Size (4), (5)
Stainless Steel
3-8 (2-4) #4, #5, #6
5-10 (3-5)
5-10 (3-5)
9-13 (4-6) #5, #6
11-15 (5-7) #6, #7, #8
11-15 (5-7)
13-17 (6-8) #8, #10
18-22 (8-10)
23-27 (11-13)
B-7
(2)
TIG TORCH