Saf-Fro DIGISTEEL III 420, Instruction For Operation And Maintenance

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7 - ANNEXES
7.1. PRESENTATION OF WELDING PROCESSES
For carbon and stainless steels, le DIGISTEEL III 420-520 / DIGIPULS III 420-520 uses 2 types of short arc:

“soft” or “smooth” short arc

The “dynamic” short arc or « SSA ».

Le short arc HPS
Pulsed MIG may be used on all types of metal (steel, stainless steel and aluminium) with solid wires and some cored wires. It is
particularly suitable for stainless steel and aluminium, for which it is the ideal process, eliminating spatter and achieving excellent
wire fusion

Characteristics of the power source arc
“Soft”or “Smooth” short arc (SA)
The “soft” short arc achieves great reduction in spatter when welding carbon steels, resulting in a very significant reduction in finishing costs.
It improves the appearance of the weld bead thanks to improved wetting of the molten pool.
The “soft” short arc is suitable for welding in all positions. An increase in wire feed speed enables entering spray arc mode but does not
avoid the globular mode transition.
Forme d’ondes du short arc doux
Note : The “soft” short arc is slightly more energetic than the "speed" short arc. Consequently the “speed” short arc may be
preferable to the "soft" short arc for the very thin sheets welding ( ≤ 1 mm) or for welding of root passes.
“
Dynamic” short arc or “Speed Short Arc” (SSA)
The Speed Short Arc or SSA allows greater versatility in welding carbon and stainless steels and absorbs fluctuations in the welder’s hand
movements, for example when welding in a difficult position. It also helps compensate for differences in the preparation of the work pieces.
By increasing the wire feed speed, the SA mode enters naturally into SSA mode, while preventing the globular mode
Thanks to its quick arc control and using appropriate programming,
DIGISTEEL III 420-520 / DIGIPULS III 420-520 can artificially extend the
Short Arc range to higher currents, in the range of the speed short arc .
Tension (Vs)
Courant (Is)
Spray Arc
Globular Arc
Speed
Short-Arc
U
1
U
2
I
1