Basic Knowledge Of The MIG Welding Process

In gas metal arc welding, a power source passes through a torch to create an arc between the incoming wire and the workpiece. The arc fuses the welding material and wire to create a weld. The wire feeder feeds the wire continuously through the torch throughout the welding process. The torch also supplies shielding gas to the weld.

The difference between MIG and MAG welding methods is that MIG (Metal Inert Gas) welding uses an inert shielding gas that does not participate in the welding process, while MAG (Metal Active Gas) welding uses an active shielding gas that participates in the welding process.

The shielding gas usually contains active carbon dioxide or oxygen, so MAG welding is more commonly used than MIG welding. In fact, people often inadvertently use the term MIG welding together with MAG welding.

MIG welding applications

Today, MIG/MAW is almost ubiquitous in the welding industry. The largest number of users are heavy and medium-heavy industries, such as shipbuilding companies, manufacturers of steel structures, pipes and pressurized vessels, and repair and maintenance companies.

MIG welding is also commonly used in the sheet metal industry, especially in the automotive industry, body shops and small industries. Hobbyists and home users also use MIG/MAG welders most often.

Welders and other equipment for MIG and MAG welding

MIG and MAG welding equipment usually consists of a power supply, wire feeder, grounding cable, welding torch, optional water cooling unit and connection to a shielding gas tank or gas network.

The function of the wire feeder is to feed the welding wire required for welding from the spool coil to the welding torch.

In addition, the wire feeder can start and stop the power supply, and when using the power supply, it can also control the voltage supplied by the power supply. Therefore, the power supply and the wire feeder are connected by a control cable. In addition, the wire feeder can also control the flow of shielding gas. The shielding gas required for welding can be obtained from gas tanks or gas pipe networks.

MIG welding machines manufactured by Kemppi are usually of modular construction, allowing you to freely choose cooling equipment, power supply and wire feeder according to your needs. The wire feeder can be detached from the power source, so there is no need to move the entire welder from one job site to another.

The device also has a replaceable control panel and other functions that can be activated individually.

The torch gets hot during welding and must be cooled with gas or liquid. In gas-cooled torches, the shielding gas flowing to the torch via the welding cable simultaneously acts as a torch tank. In water-cooled torches, a separate water-cooling unit is required to circulate the coolant from the welding cable into the torch.

The structure of a MIG/MAG welder is constrained by the welding wire coil inside the welder. Coils are usually relatively heavy and space-consuming components. Even so, the latest MIG/MAG welders are sleek, compact welding packages such as the Kemppi MinarcMig Adaptive 180, which won the industry's Red Dot Award for design in 2006.

MIG welding technology

In gas metal arc welding, the tool used by the welder is a welding torch. The welding torch is used to direct the filler wire, shielding gas and required welding current to the workpiece. The most important issues associated with MIG/MAW are welding position, torch angle, wire stick out, welding speed, and weld pool shape.

Ignite the arc with the torch switch in the torch, then move the torch along the weld bead at a steady welding speed. The formation of molten welds must be observed. The position and distance of the welding torch relative to the workpiece must remain constant.

It is especially important that the welder should remain focused on managing the molten weld. A little carelessness increases the risk of soldering problems. If this happens, it is best to temporarily interrupt welding before continuing.