Arc welding, Shielded metal arc welding, Metal Inert gas welding
Gas Metal Arc Welding GMAW Modes of Metal Transfer Spray Globular Short Circuiting Pulsed Spray Gas...
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Transcript of Gas Metal Arc Welding GMAW Modes of Metal Transfer Spray Globular Short Circuiting Pulsed Spray Gas...
Gas Metal Arc WeldingGas Metal Arc Welding
GMAW Modes of Metal TransferSpray Globular
Short Circuiting Pulsed Spray
Gas Metal Arc Welding
GMAW Filler Metal Designations
ER - 70S - 6
Electrode
Rod (can be used with GMAW) Minimum ultimate tensile
strength of the weld metal
Solid Electrode
Composition6 = high silicon
AWS Specifications for GMAW Wire
AWS A5.18 - Carbon Steel ElectrodesAWS A5.28 - Low Alloy Steel Electrodes
Shielding Gas
• Shielding gas can affect– Weld bead shape– Arc heat, stability,
and starting– Surface tension– Drop size– Puddle flow– Spatter
Ar Ar-He He CO2
Gas Metal Arc Welding
GMAW Advantages• Deposition rates
higher than SMAW
• Productivity higher than SMAW with no slag removal and continuous welding
• Easily automated
Gas Metal Arc Welding
Quality• Spatter
– Droplets of electrode material that land outside the weld fusion area and may or may not fuse to the base material
• Porosity – Small volumes of
entrapped gas in solidifying weld metal
Gas Metal Arc Welding
Limitations• Equipment is more
expensive and complex than SMAW
• Process variants/metal transfer mechanisms make the process more complex and the process window more difficult to control
• Restricted access– GMAW gun is larger than
SMAW holder
Gas Metal Arc Welding