Lincoln Electric SVM185-A service manual 109, Gmaw-Stt

B-21 OPERATION B-21

GMAW-STT™

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Waveform Control Technology™ maximizes the ability to modify the arc for the perfect weld. When STT™ welding, the parameters to control are:

•Wire Feed Speed - sets the deposition rate.

•Peak Current - controls the arc length.

•Background Current - regulates the bead contour.

•Tail-out - provides additional power in the arc.

There is no Voltage control when STT™ welding.

220

WFS AMPS

LessMore

Deposition Deposition

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VOLTS TRIM

MSP4 OPERATION

WELD MODES

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ELECTRODE AND GAS				WIRE SIZE
				0.035	0.045	0.052
STEEL CO2		Ar/CO 2		110	126	126
STAINLESS		He/Ar/CO2		110	126	126
(with Hot Start)
STEEL CO2		Ar/CO 2		123	124	124
STAINLESS		He/Ar/CO2		123	124	124
(SYNERGIC STT)				111	117	120
STEEL	CO2
STEEL	AR/CO2			112	118	121
STAINLESS He/Ar/CO2				127	129	---
STAINLESS Ar/CO 2				131	133	---
SYNERGIC STT, OPEN ROOT
STEEL	CO2			113	119	122
STAINLESS He/Ar/CO 2				135	137	---
		WAVEFORM CONTROL TECHNOLOGY
IR PORT		109		Steel
				.035"
		STT				SETUP
WELD MODE						START OPTIONS
ARC CONTROL						END OPTIONS
			SET
		ARC CONTROL
EFFECT / RANGE			DESCRIPTION
PEAK CURRENT		Peak Current acts similar to an arc pinch
		control. Peak Current sets the arc length
		and promotes good fusion. Higher peak

current levels will cause the arc to broaden momentarily while increasing arc length. If

set too high, globular transfer may occur.

Setting it too low may cause instability and wire stubbing. Best practice is to adjust for minimum spatter and puddle

agitation.

B A C K G R O U N D Background Current controls the overall

CURRENT	heat input in the weld.
TAIL OUT	Tail out provides additional power
( STT ll	MODES without the molten droplet becoming
ONLY)	too large. Increase as necessary to add
	heat input without increasing arc length.
	Often this results in faster travel speeds.
	Note that as tail out increases, the peak
	current and/or background current may need
	to be reduced.

START OPTIONS

PREFLOW TIME	FUNCTION
0 - 10 seconds	Adjusts the time that shielding
	gas flows after the trigger is
	pulled and prior to feeding wire.
RUN-IN WFS:	Run-in sets the wire feed

Off, 50 to150 in/min. speed from the time the trigger is pulled until an arc is estab-

	lished.
Start Procedure	The Start Procedure is not
	commonly used with STT
	procedures.

-

END OPTIONS

PARAMETER	FUNCTION
RANGE
Postflow Time:	Adjusts the time that shielding
0 to 10 seconds	gas flows after the welding out-
	put turns off.
Burnback: 0 to .25	The burnback time is the
Seconds	amount of time that the weld
	output continues after the wire
	stops feeding. It prevents the
	wire from sticking in the puddle
	and prepares the end of the
	wire for the next arc start.
Crater Procedure	Crater is not commonly used
	in STT weld procedures.

POWER FEED® 25M