Gas Metal Arc Welding (GMAW) Transfer Modes
There are 3 different type of transfer modes that are used with GMAW. The first type we will talk about is Short Circuit which is a very typical type of transfer mode that is used everywhere. The second type we will talk about is Globular transfer mode. And the third transfer type we will talk about is Spray Transfer. Each of which are determined by; type of welding current and magnitude, shielding gas type, electrode diameter and composition, and how far the electrode stickout is.
Short Circuit transfer mode works by the electrode making contact with the Base Material then snapping off due to the resistance heating the wire and then melting off, after a puddle is formed the electrode makes contact with the weld pool to do the same thing. This is repeated at a rate of 20-200 times per second which allows you to make a weld.
Globular transfer mode happens when a molten droplet is formed on the end of the electrode then drops off due to gravity or from short circuiting. This droplet has to be at a larger diameter than the electrodes diameter to be considered globular transfer.
This transfer mode is the hottest and most efficient transfer mode. The arc is started by the wire coming in contact with the base material then burning back, the end of the wire will have a needle like point and the filler material will be spraying across the arc in tiny droplets.