What Are the Transmission Modes of Gas Metal Arc Welding?

Understanding Gas Metal Arc Welding

Gas metal arc welding, also known as TIG welding, is one of the most common types of welding. In the gas metal arc welding process, an arc is formed between the metal and the wire electrode, heating the metal. This action melts the parts and fuses them together to form a permanent bond. Gas metal arc welding emerged in the late 1940s when continuously fed electrode wire replaced the tungsten electrode in gas metal arc welding (GTAW) processes. It quickly gained popularity because it was more cost-effective than GTAW. Today, gas metal arc welding is used in various industries ranging from construction and manufacturing to racing and automotive production.

Another term for gas metal arc welding process is metal inert gas welding. In both MIG and gas metal arc welding process, a continuous solid wire electrode passes through the welding gun along with a shielding gas to protect it from contaminants in the air. This welding process can be used on thick and thin metal plates as well as aluminum and other nonferrous materials.

Types of Gas Metal Arc Welding

There are several different techniques available for transferring the weld metal from the arc to the base metal in gas metal arc welding. These transfer modes are:

• Short circuit: The coldest form of gas metal arc welding process is achieved by using a low voltage short circuit. The wire contacts the metal, and the current flows through the welding gun, forming a short circuit. The result is a wet metal puddle that quickly solidifies and fuses the materials together.

• Spray: In the spray transfer mode, the wire melts into tiny droplets that are sprayed or atomized into the weld. It is a constant voltage process that uses a high heat input to deliver a constant flow of welding metal from the arc to the base material.

• Globular: The globular transfer method is similar to the short circuit method. The wire electrode is arced and contacts the base metal. However, the heat input is higher, and the wire is heated for a longer period of time. This creates a larger puddle that collects at the tip of the welding gun and drips into the joint.

• Pulsed: Pulsed spray transfer is similar to the spray arc method but with modifications to eliminate potential drawbacks. The welding machine pulses the voltage multiple times per second, causing the wire end to form droplets and be pushed through the arc into the molten puddle. This is the most practical and flexible transfer mode but also the most expensive since it requires a high-end gas metal arc welding machine.