Page 166 - CITS - Welder - Trade Theory

WELDER - CITS

It permits welding thinner sections with greater ease, and is extremely practical for welding in all positions.
d Pulsed spray transfer (Fig 4)
Pulsed spray transfer has a steady stream of metal drop-lets crossing the welding arc. The pulsed power source
supplies the welding arc with two types of welding current.

Fig 4

Peak current - this current allows the formation of metal droplets which then cross the welding arc.
Background current - the background current will keep the arc alive, but doesn’t allow for any weld metal
transfer.
Pulsed spray transfer allows time for the weld puddle to freeze a little on the background current cycle, which
allows for
i more control of the weld puddle.
ii more time for impurities to float to the top of the weld pool resulting in cleaner and stronger welds.

Advantages
a able to spray thinner metals
b less heat input
c stronger welds
d more weld control
e out-of-position welding

f Little spatters
Disadvantages
a higher set up costs
b needs operator training

c lower deposition rate

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CITS : C G & M - Welder - Lesson 49 - 60