Firepower MST 140i, Руководство по эксплуатации

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Firepower MST 140i
Manual 0-5338 4-3 BASIC WELDING GUIDE
Preselected Variables
Preselected variables depend upon the type of material being welded, the thickness of the material, the welding position, the
deposition rate and the mechanical properties. These variables are:
• Type of electrode wire
• Size of electrode wire
• Type of gas (not applicable to self shielding wires FCAW)
• Gas flow rate (not applicable to self shielding wires FCAW)
Primary Adjustable Variables
These control the process after preselected variables have been found. They control the penetration, bead width, bead height,
arc stability, deposition rate and weld soundness. They are:
• Arc Voltage
• Welding current (wire feed speed)
• Travel speed
Secondary Adjustable Variables
These variables cause changes in primary adjustable variables which in turn cause the desired change in the bead formation.
They are:
1. Stick-out (distance between the end of the contact tube (tip) and the end of the electrode wire). Maintain at about
3/8" (10mm) stick-out
2. Wire Feed Speed. Increase in wire feed speed increases weld current, Decrease in wire feed speed decreases weld
current.
Art # A-08997_AD
Gas Nozzle
Electrode Wire
Average Arc Length
Electrode Stick-Out
Tip to
Work Distance
Actual Stick-out
Contact Tip (Tube)
Figure 4-8
3. Nozzle Angle. This refers to the position of the welding MIG Gun in relation to the joint. The transverse angle is usually
one half the included angle between plates forming the joint. The longitudinal angle is the angle between the centre
line of the welding MIG Gun and a line perpendicular to the axis of the weld. The longitudinal angle is generally called
the Nozzle Angle and can be either trailing (pulling) or leading (pushing). Whether the operator is left handed or right
handed has to be considered to realize the effects of each angle in relation to the direction of travel.
Transverse and Longitudinal
Nozzle Axes
Art # A-08998_AB
Longitudinal
Angle
Axis of Weld
Transverse
Angle
Figure 4-9