|
|
Mig | Tig | Arc | Encyclopedia | CNC | Welding News | Home |
The Welder's Corner
By Welders, For Welders - Articles, Blog and Metalworking
Welding Equipment Comparisons, Topics, and information
-
See the Welding News Blog, for in depth information on the issues and news that welders and welding companies face.
Also, information, articles, and advice for plasma cutters, CNC equipment & more.
What is MIG Welding?
MIG welding is an arc welding process that joins metals by heating them with an arc. MIG and flux cored welders offer advantages over other welding processes for both new and veteran welders. The welding machine creates an arc between the metal and a consumable electrode, known as the mig welders wire.
The operator concentrates on directing the MIG welder gun at the joint and proper motion. Most MIG welders can also flux cored weld.
Mig welders use aluminum alloy wire
Gas Metal Arc Welding (GMAW) is frequently referred to as MIG welding. It is a commonly used high deposition rate welding process. Wire is continuously fed from a spool. MIG is a semiautomatic welding process
Externally supplied gas or gas mixtures provide shielding for mig welders. Common MIG welding is also referred to as short circuit transfer. Metal is deposited only when the wire actually touches the work. No metal is transferred across the arc.
Spray transfer
Another method of MIG welding, spray transfer moves a stream of tiny molten droplets across the arc from the electrode to the weld puddle. Consumables: contact tips, shielding gas, welding wire.
Mig welders use direct current power source, with the electrode positive. The metal is transferred from the filler wire to the weld bead by magnetic forces as small droplets called spray transfer. This gives the mig welder deep penetration and makes it easy to weld in all positions. It is important for the quality of the weld that the spray transfer is obtained.
There are two different MIG welding processes, conventional MIG welders and pulsed MIG welders
MIG welders use a constant voltage DC power source. Since the spray transfer is limited to a certain range of arc current, the conventional MIG welder process has a lower limit of arc current. This also limits the application of conventional MIG to weld material thicknesses above 4 mm.
Pulsed MIG welders use a DC power source with superimposed periodic pulses of high current. Pulsed MIG welding is possible to operate with lower average current and heat input compared to conventional MIG welders. This makes it possible to mig weld thinner sections and weld much easily in difficult welding positions.
Recommended material thicknesses for MIG-welding aluminum
-
Conventional MIG-welding: with or without backing: > 3 mm
-
Pulsed MIG-welding: > 1 mm. Smaller thicknesses are possible, however with thinner diameter on welding wire.
-
For MIG welding of thick plates preheating of 50ñ100ƒC may be required to avoid lack of fusion.
Copyright 2010 Welder's Corner | Privacy Policy | Contact us