Lincoln Electric IM836-B manual TIG Welding, Typical Current Ranges 1 for Tungsten ELECTRODES2

B-5 OPERATION B-5

The Ranger 305D can be used with a broad range of DC stick electrodes. The MODE switch provides two stick welding settings as follows:

Constant Current (CC-STICK) Welding

The CC-STICK position of the MODE switch is designed for horizontal and vertical-up welding with all types of elec- trodes, especially low hydrogen. The output CONTROL dial adjusts the full output range for stick welding.

The ARC CONTROL dial sets the short circuit current (arc-force) during stick welding to adjust for a soft or crisp arc. Increasing the number from -10(soft) to +10(crisp) increases the short circuit current and prevents sticking of the electrode to the plate while welding. This can also increase spatter. It is recommended that the ARC CON- TROL be set to the minimum number without electrode sticking. Start with the dial set at 0.

DOWNHILL PIPE Welding

This slope controlled setting is intended for "out-of-posi- tion" and "down hill" pipe welding where the operator would like to control the current level by changing the arc length. The output CONTROL dial adjusts the full output range for pipe welding. The ARC CONTROL dial sets the short circuit current (arc-force) during stick welding to adjust for a soft or more forceful digging arc (crisp). Increasing the number from -10(soft) to +10(crisp) increases the short circuit current which results in a more forceful digging arc.Typically a forceful digging arc is pre- ferred for root and hot passes. A softer arc is preferred for fill and cap passes where weld puddle control and deposi- tion (“stacking” of iron) are key to fast travel speeds. This

can also increase spatter. TABLE B.2

It is recommended that the ARC CONTROL be set to the minimum number without electrode sticking. Start with the dial set at 0.

TIG WELDING

The TOUCH START TIG setting of the MODE switch is for DC TIG (Tungsten Inert Gas) welding. To initiate a weld, the 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 volt- age or current and, in general, no tungsten contamina- tion. 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 dial is used to set the maximum current 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 current 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.

The RANGER 305 D can be used in a wide variety of DC TIG welding applications. In general the ʻTouch Startʼ feature allows contamination free starting without the use of a Hi-frequency unit. If desired, the K930-2 TIG Module can be used with the RANGER 305 D. The settings are for reference.

TYPICAL CURRENT RANGES (1) FOR TUNGSTEN ELECTRODES(2)

Tungsten Electrode		DCEN (-)	DCEP (+)	Approximate Argon Gas Flow					TIG TORCH
Diameter in. (mm)				Flow Rate C.F.H. ( l		/min.)			Nozzle Size (4), (5)
		1%, 2% Thoriated	1%, 2% Thoriated	Aluminum			Stainless Steel
		Tungsten	Tungsten
.010	(.25)	2-15	(3)	3-8	(2-4)		3-8	(2-4)	#4, #5, #6
0.020	(.50)	5-20	(3)	5-10	(3-5)		5-10	(3-5)
0.040	(1.0)	15-80	(3)	5-10	(3-5)		5-10	(3-5)
1/16	(1.6)	70-150	10-20	5-10	(3-5)		9-13	(4-6)	#5, #6
3/32	(2.4)	150-250	15-30	13-17	(6-8)		11-15	(5-7)	#6, #7, #8
1/8	(3.2)	250-400	25-40	15-23	(7-11)		11-15	(5-7)
5/32	(4.0)	400-500	40-55	21-25	(10-12)		13-17	(6-8)	#8, #10
3/16	(4.8)	500-750	55-80	23-27	(11-13)		18-22	(8-10)
1/4	(6.4)	750-1000	80-125	28-32	(13-15)		23-27	(11-13)

(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	EWP
1% Thoriated	EWTh-1
2% Thoriated	EWTh-2

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 and high duty cycles.

RANGER 305D