MIG WELDING

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 than SMAW  Less operator skill required  Long welds can be made without starts and 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 to the molten weld pool.  There are three primary metal transfer modes:  Spray transfer (MP3 Audio)  Globular transfer (MP3 Audio)  Short circuiting transfer (MP3 Audio) The primary shielding gasses used are:  Argon  Argon - 1 to 5% Oxygen  Argon - 3 to 25% CO2  Argon/Helium CO2 is also used in its pure form in some MIG welding processes.  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

We can help optimize your MIG welding process variables. Evaluate your current welding parameters and techniques.  Help eliminate common welding problems and discontinuities such as those listed below:

Weld Discontinuities  Undercutting  Excessive melt-through  Incomplete fusion  Incomplete joint penetration  Porosity  Weld metal cracks  Heat affected zone cracks

MIG Welding Problems

•  Heavily oxidized weld deposit
•  Irregular wire feed
•  Burnback
•  Porosity
•  Unstable arc
•  Difficult arc starting