Arc Welding Process - MIG Welding
Gas Metal Arc Welding (GMAW) is frequently referred to as MIG welding. MIG welding is a commonly used high deposition rate welding process. Wire is continuously fed from a spool. MIG welding is therefore referred to as a semiautomatic welding process.
MIG Welding Benefits
All position capability. Higher deposition rates that SMAW. Less operator skill required. Long welds can be made without starts or stops. Minimal post weld cleaning is required.
Mig Welding Shielding Gas
The shielding gas forms the arc plasma, stabilizes the arc on the metal being welded, shields the arc and molten weld pool, and allows smooth transfer of metal from the weld wire pool. There are three primary metal transfer modes: Spray transfer, Globular transfer, and Short circuiting transfer. The primary shielding gasses used are: Argon, Argon-1 to 5% Oxygen, Argon-3 to 25% CO2, and Argon/Helium. CO2 is also used in its pure form in some mig welding processed. However, in some applications the presence of CO2 in the shielding gas may adversely affect the mechanical properties of the weld.
Common MIG Welding Concerns
Weld discontinuities. Undercutting. Excessive melt-through. Incomplete fusion. Incomplete joint penetration. Porosity. Weld metal cracks.
MIG Welding Problems
Heavily oxidized weld deposit. Irregular wire feed. Burnback. Porosity. Unstable arc. Difficult arc starting.
Related Topics
- Advantages of MIG Welding
- Automated MIG Welding of Aluminum
- Bernard to Showcase MIG Welding Products and Resources
- Cold metal transfer MIG welding is spatter-free
- CR-Rom explains pulsed-MIG welding
- Introducing Pulsed MIG Welding
- Metal-Cored Wire is suited for robotic MIG welding
- MIG Welding Information
- Mig Welding Tips
- MIG welding tips and resources