GMAW

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GMAW Gas Metal Arc Welding
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• Definition
• GMAW Gas Metal Arc Welding Solid wire is
  fed into the weld pool, the wire is consumed and
  becomes part of the weld pool. The weld pool
  must be protected with a shielding gas.
• FCAW Flux core arc welding Wire is hollow and
  contains a flux that vaporizes and shields the
  weld pool.
• DSAW Dual Shield Flux core wire is used in
  conjunction with a shielding gas.
• SAW Weld pool is submerged in a dry granular
  flux.

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Typical Wire Feed Setup
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Typical Flux Core Setup
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Typical Submerged Arc Setup
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Advantages and Disadvantages

• Advantages
• Clean (GMAW)
• Fast
• Attractive
• Low skill level
• Not good on dirty material
• Easily Automated

• Disadvantages
• Flux core dirty
• Lots of moving parts
• More expensive to buy and
• setup
• Need to purchase gas
• Less penetrating
• Sometimes difficult to set up
• Tough in the wind

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Metal Transfer Open Arc Spray Transfer (6-12
Lbs/Hr) Globular Transfer (4-7 Lbs/Hr) Pulsed
Transfer (2-6 Lbs/Hr) Short Circuit (2-6
Lbs/Hr)
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Short Circuit Transfer Definition transfer
takes place only when wire touches the base
material
Low Current Low Wire speed Low Voltages Low Heat
Low Distortion Great for overhead Great of
filling gaps
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Open Circuit Transfer Definition transfer
takes place without contacting the base material
Types Globular Spray Pulsed
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Globular Transfer Definition Metal is
transferred across the arc in large irregularly
shaped drops
Causes Splatter Lower amperage is
needed Common Can have good effect with submerged
arc
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Spray Transfer Definition Uses a mixture of
gas and amperage to provide smaller droplet size
to give a superior weld.
High Heat Fine Droplets Splatter Free Deep
Penetration
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Spray Transfer Gas
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Pulsed Transfer Definition Pulses spray
transfer allowing for lower heat during transfer.
Advantages of spray transfer at lower
amperages. Expensive equipment Uses larger
diameter electrode Most pulse rates are 60 to 120
pulses per second.
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Shielding Gas
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Travel