Lincoln Electric IM649 manual Find the Optimal Arc Characteristics

Appendix B STT WAVE SHAPING PRINCIPLES B-9

2. Find the Optimal Arc Characteristics

Use the following weld trials and adjustment sequence to tune the selected waveform for your weld application at the designated workpoint (wire feed speed). Weld trials and adjustments are more easily performed with one person welding while you adjust the waveform parameters at the computer terminal.

a.Set the Invertec Trim control for a readout of 1.00. This will ensure that the wave shape is designed at the midrange of the trim adjustment capability. The welding machine’s trim control allows the welder to adjust the arc length between 0.5 to 1.5 (50% to 150%) times the established arc length adjustment factor.

b.Maintain a constant stickout. The stickout should be equal to the expected average of the welding application. We recommend about 5/8 in. to 3/4 in. (16 mm to 19 mm) electrical stickout.

c.While welding a trial weld bead, adjust the waveform variables (peak current, background current, tailout, etc.) to achieve a desired droplet transfer with a fixed 5/8 in. to 3/4 in.

(16 mm to 19 mm) stickout at the selected wire feed speed. Refer to paragraph B.5.

d.With the stickout at a fixed setting, make trail welds during each adjustment so you can directly observe the effect of the adjustments in the arc and resulting weld. Adjust the variables as needed to achieve the desired weld transfer at the fixed stickout.

NOTE: Wire feed speed controls the deposition rate. Peak current controls the arc length. Background current controls the bead contour, and tailout adjusts power (heat) in the arc. For optimum spatter control, the arc should be focused on the weld puddle.

					PEAK TIME
AMPERES					PEAK AMPS
					TAILOUT
	PINCH START	CALCULATEdV/dt
					SPEED
	BACKGROUND AMPS
				TIME
			27850059

WAVE DESIGNER