Linde BOC Smootharc Advance MIG 425R Operating Manual page 32

32 BOC Smootharc Advance III MIG 425R & 555R Operating manual
Typical Metal Transfer Mode
Dip
Transfer
Process
Metal Inert Gas
✓
(MIG)
Flux Cored
✓
(Gas Shielded)
Flux Cored
✓
(Self Shielded)
✓
Metal Cored
* Not True Spray
Common Materials Welded with BOC MIG Wire
Material
AS2074 C1,C2,C3, C4-1,C4-2,C5,C6
BS3100 AW1,A2,A3
BS1504-430,480,540
ASTM A36,A106,EN8,8A
Stainless Steel
Grade 304
Grade 309
Grade 316
Physical condition
Surface condition
The welding wire must be free from any surface contamination including
mechanical damage such as scratch marks.
A simple test for checking the surface condition is to run the wire through a
cloth that has been dampened with acetone for 20 secs. If a black residue is
found on the cloth the surface of the wire is not properly cleaned.
Cast and Helix
The cast and helix of the wire has a major influence on the feedability of MIG
wire.
If the cast is too large the wire will move in an upward direction from the tip
when welding and if too small the wire will dip down from the tip. The result
of this is excessive tip wear and increased wear in the liners.
If the helix is too large the wire will leave the tip with a corkscrew effect.
Globular
Spray Transfer
Transfer
✕ ✓
✓ ✓*
✓ ✕
✕ ✓
BOC MIG Wire
BOC Mild Steel MIG Wire
BOC Mild Steel MIG Wire
BOC Mild Steel MIG Wire
BOC Mild Steel MIG Wire
BOC Stainless Steel 308LSi
BOC Stainless Steel 309LSi
BOC Stainless Steel 316LSi
Cast and Helix
Cast
Cast – Diameter of the circle
Helix – Vertical height
Selection of the Correct Power Source
Power sources for MIG welding is selected on a number of different criteria,
including:
1
Maximum output of the machine
2
Duty cycle
3
Output control (voltage selection, wire feed speed control)
4
Portability
The following table gives an indication of the operating amperage for
different size wires.
Wire Size Amperage Range (A)
0.8 mm 60–180
0.9 mm 70–250
1.0 mm 90–280
1.2 mm 120–340
Selection of the Correct Polarity on the Power Source
Many power sources are fitted with an optional reverse polarity dinse
connector.
To achieve the optimum welding it is important to adhere to the consumable
manufacturer's instruction to select the polarity.
As a general rule all solid and metal cored wires are welded on electrode
positive. (Work return lead fitted to the negative connector.)
Some grades of self shielded flux cored wires (i.e. E71T-11, E71T-GS etc) need
to be welded on electrode negative. (Work return lead fitted to the positive
connector.)
Helix