While it may be one of the easier forms of welding, that does not mean that everyone understands or is able to do it. An experienced welder is needed to use this technique, one who is well-trained and who follows all safety guidelines. This article looks to explain what MIG welding is and when it is used.
What is MIG Welding?
MIG welding goes under many different names. Its proper name is gas metal arc welding (GMAW). It is also referred to as metal inert gas welding or metal active gas welding. It can both function as a semi-automatic or an automatic arc welding process.
This type of welding is used quite extensively in high production welding operations. Almost all commercially important metals can be linked using this process, including stainless steel, carbon steel, aluminum, and copper. Each of these materials can be welded together in all positions simply by choosing the right shielding gas, welding conditions, and electrode
The shielding gas helps to protect the weld from any type of contaminants, such as dirt or moisture. The constant voltage that is applied creates a direct current power source, which is then used to produce the arc. The voltage is controlled by the automatic adjustment and applies a constant power supply that heats the metal, making it easy to weld pieces together.
It Has Come a Long Way
MIG welding was first invented back in 1940. Its initial purpose was for welding aluminum and other non-ferrous materials. By the 1950s, developments had occurred that made the process even more versatile. This helped it to become one of the primary welding processes used in major industry. Today, that is still true. This form of welding is often used in the automobile industry, not only because of its great versatility but also because of how quickly and efficiently welds can be produced.
While there have been major developments in the process, one issue has remained true from the start. Because of the shielding gas that is produced, MIG welding cannot be performed outdoors. Weather conditions and debris pose a serious risk to weaken the weld.
We Need More Power
While this is not true in every case, the vast majority of MIG welding applications will require that a direct current reverse polarity, also known as electrode positive, be applied. This electrical connection provides the stable arc that is necessary for a smooth metal transfer. It also decreases spatter, meaning that there is little waste involved. The bead becomes true and clean.
In direct current straight polarity, also known as electrode negativity, the arc can become unstable, maybe even erratic. The melting rate is much higher than that achieved with the electrode positive. This is why it is used sparingly in comparison. An expert welder is needed to use this form of MIG process. Some areas even require a special certification for its use.
Major Applications of MIG Welding
- Automotive industry. As mentioned before, this type of welding is often used in the automotive industry. The reasons behind this are obvious. First off, welds can be processed quickly and provide a solid blending. In an automobile, it is essential that metals stay firmly connected to one another.
The MIG welding process works perfectly, because cars can be properly welded as they move down the assembly line. The process happens quickly and efficiently and is often automated to ensure that welds are properly sealed.
- Pipe Industry. This is not as only application, however. Many large-scale industries use MIG welding, such as pipe industries. The same benefits are present for the pipe industry that is present in the automotive industry.
While the weld may not look perfectly clean and every instance, it is unimportant. Because the metal is sanded down or airbrushed and then painted, no one would notice any blemish or splatter from the weld. It is a perfect solution for a very fast-paced industry.
- Bridge construction. When building bridges, MIG welding is quite commonly used. Once again, no one is concerned with exactly how the weld of two metal pieces looks on a bridge. What they are concerned about is the durability involved. How much tension and pressure can the bridge withstand, and this type of welding provides the perfect solution to answer that question.
The one concern about using this type of welding in bridge building is how the elements will affect the integrity of the weld. Fortunately, there have been several innovations that have helped to improve the quality of the welds, eliminating any concern.
The Advantages and Disadvantages
Like any other process in life, there are both advantages and disadvantages to using MIG welding.
- It is one of the fastest welding processes available.
- Provides for greater deposition rates.
- It does not require the most skilled operator to use this type of welding.
- It is a type of welding process that can be learned quite easily.
- It does not require a filler metal to work.
- Provides an outstanding quality weld.
- It is a clean and efficient welding process that leaves very little slagged or chip in the weld.
- This type of welding process can be automated quite easily.
- Little cleaning is needed after the weld is completed.
- Costs to set up an MIG weld can be expensive.
- The radiation effect that is created can be quite severe.
- The maintenance costs of this type of welding equipment, especially the automated ones can be costly.
- It does not allow for welding and all positions.
- Thick metals cannot be welded using this process.
As you can see, there are some disadvantages to using this welding process. However, MIG welding has proven itself to be one of the best options available. It’s why large industries are finding that there is no better option available to them.