Pound for pound of filler metal used, MIG welding (Metal Intert Gas, also known as GMAW) is one of the most popular welding processes. A key contributor to the success of the process is its versatility: it can produce high-quality welds with good productivity on a range of material thicknesses and compositions.
MIG welding uses a continuously fed wire electrode to transmit the welding arc and provide filler metal into the weld joint. The weld is protected from the atmosphere by an external shielding gas whose specific composition is often determined by the application, although as the name implies, it is largely inert.
Shop Fabrication Manufacturing
Because shielding gas is required, MIG is not commonly used for field fabrication and repair since providing protection from draft and breeze is time-consuming and can be difficult. Instead, self-shielded processes such as FCAW-S or stick welding (SMAW) are more popular.
Common Industry Applications of MIG Welding
The welding filler metal used may be solid or tubular. Tubular MIG welding wires/electrodes are often known as metal cored wires: they are a hollow tube filled with metal alloys. These tubular filler metals have some advantages over solid wires, such as potential deposition rate/productivity, although at the expense of per-pound filler metal cost. Metal cored wires are especially common in the fabrication of heavy equipment components and structural members.
Both solid and metal cored wires produce little to no slag, post-weld clean-up time is minimal, meaning parts can often be sent to downstream processes such as painting using only a light scrub with a wire brush. This makes the process very attractive for applications that demand high productivity, such as manufacturing.
Common Metals
The MIG welding process is used for welding carbon and low alloy steels, aluminum, and stainless steel. This means that it is common to industries ranging from boat and shipbuilding to chemical refineries.
Compared to steel and stainless steel wire, aluminum MIG wire takes special care in order to feed properly. Purpose-built components such as Teflon guides and liners, U-shaped drive rolls, and push-pull or spool guns are designed to help feed aluminum wire with less difficulty.
Filler metals for stainless steel welding are available in a wide range of alloy compositions ranging from the most common austenitic alloys (for example, 308L for welding 304/304L) to more exotic duplex stainless steels. MIG welding wires are even available for nickel super alloys, although many of these are tubular metal cored wires.
Thin Thick Materials
MIG welding is frequently used for welding thin materials thanks to the availability of small diameter wires—0.023” to 0.035”—and pulsed waveforms. Both wire and waveform help provide a stable arc at the low amperages needed to produce a high-quality weld without burn-through or excessive weld size. Thin materials welded with MIG are often encountered when manufacturing automotive components. However, MIG is also an excellent process for the garage and home hobbyist.
Common Industry Applications of MIG Welding
MIG welding also exhibits good deposition rates and good performance at medium-to-high amperages, which means it is a popular choice for thick materials in addition to thin ones. Because the process is more easily observed during welding and used handheld than “faster” processes such as submerged arc, one could argue that the process is much more versatile and allows tackling a complex assembly with a single process. However, when thick metals must be welded out-of-position frequently, the gas-shielded flux cored welding (FCAW-G) process is preferable, since the slag offered by these consumables facilitates welding at amperages that help ensure good fusion along with good productivity. Fortunately, MIG equipment is often suitable for FCAW with only a change in filler metal and drive roll type.
An advantage of welder rentals is the opportunity to accomplish the task at hand with the equipment best suited for that task. If you don’t expect to weld thick material all the time, you can utilize heavy-duty equipment only when needed without the ROI demand and capital commitment of outright purchase. This is of extreme benefit to job-shop fabricators who can encounter everything under the sun, or field fabricators who may spend most of their time with an engine-driven unit but are able to utilize MIG infrequently, yet capitalize on higher productivity.
Pipe Welding
As mentioned, out-of-position welding may not be preferable for many MIG welding applications, but the process has exceptional performance when placing an open-root root pass on tubes and pipes. Because of the low amperages used, this may be done easily in- or out-of-position. Newer power sources have modified waveforms that help further the ease-of-use and weld quality root pass welding.
MIG welding may not be used for higher amperage fill and cap passes on pipes in a fixed position, but it is extremely popular when the pipe can be rotated. Typically, pipes ranging in diameter from 2-24” are welded using MIG, although there is some overlap with other processes at either end of this range.
Automation Mechanization
MIG is one of the most popular processes for automation and mechanization. This is largely because the process is “semi-automatic”, allowing ease in programming and obtaining a high operator factor. The MIG welding torch is quite light, allowing ease of mounting to a range of robot arms. Special power sources offer improved ease of integration into the robotic system and welding cell, high amperage output and duty-cycle for improved travel speeds and uptime. Large drums of wire can be used to minimize downtime spent changing filler metal packaging.
Common Industry Applications of MIG Welding
Conclusion
MIG welding supports such a vast array of industries and applications that the ones mentioned above are by no means an exhaustive list. Instead, take these examples as inspiration to how MIG can be implemented into your operations. If you aren’t sure of the best route, contact us today to learn more about selecting the best welding equipment for your particular application. Our expert staff can also provide insight to productivity enhancing accessories, parameters, and techniques to ensure that your time spent MIG welding is successful!
