Welding is a technological process that helps us make monolithic joints that cannot be dismantled. This process has a wide application in production industry, construction, car industry and in other spheres because the metal elements that are made with welding have a more light and simple construction compared to the constructions whose elements are connected with other types of technology.
The currently used welding methods are many, but the most popular types are mainly two: MIG and MAG welding
What is MIG and MAG welding?
Both welding methods are applied in a protected gas environment. One of the differences between them is that MIG welding is done with a non-consumable electrode and MAG welding is done with a consumable electrode.
We will check each of the welding methods to understand their differences in the technological process.
MIG welding method
Generally speaking, MIG welding is done with an electrical arc and non-consumable material (electrode) is used.
The electrodes used in MIG welding are usually made from pure tungsten or yttrium/lanthanum alloy tungsten.
The protected environment is usually made of pure argon (99,98%), argon + oxygen or technical helium.
Working principle of mig welding
This welding method includes arc welding in which the arc is created between the electrode and the material that will be processed.
The arc can be supplied with either constant or variable electric supply. The use of constant electric supply in MIG welding can be applied for all metals without aluminum, magnesium or some of their alloys. The arc that is created by using constant electric supply have а high burn level and better heat concentration on the processed metal.
Because in this type of welding process the arc needs to melt the metal, it’s mostly applied for products that have a width no more than 4 - 5 mm.
MIG welding can be done manually or mechanically. In manual welding the welder should be held in one hand and the additional element (the electrode) in the other. While in mechanical welding the welding torch and the welding wire are moved automatically.
Besides, welding can be done with or without additional material (tungsten electrode or wire).
The types of additional materials used in MIG welding depend on the electricity type. The electrodes used in welding with a constant electrical supply are made of tungsten and other materials, while welding with a variable electric supply includes electrodes made of pure tungsten.
Advantages:
- With this welding method we can process all types of metals;
- Welding quality is very high;
- There is no spatter or dross during the welding process which means that the welded elements don’t need further processing for smoothing the rough spots;
- MIG welding can be applied in all types of positions in space
Disadvantages:
- This method for welding offers low efficiency because it works at a low speed and the method’s level of efficiency depends on the welder’s qualification level;
- It’s possible for the detail that is welded to be deformed by the heat which will cause considerable deformities on the end product;
- The strength and the quality of the welding depend on qualification and abilities of the welder.
Application:
This welding method finds a wide application not only in production but it’s also a preferred method for welding metals at home.
MIG welding is developed in the middle of the last century for the needs of aviation. The first protective gas used in welding was technical helium.
This welding method has different names in each country and its international name is
- TIG -T = Tungsten, I = Inert, G = Gas.
- In Bulgaria is called “ВИГ” - В = tungsten, И = inert, Г = gas,
- IN USA - GTAW - G = Gas T = Tungsten A = Arc W = Welding
- in other European countries it is called WIG - WIG - W = Wolfram I = Inert G = Gas.
At the beginning we have mentioned that in order to understand the differences between the main welding methods we need to understand first what MIG and MIG/MAG welding are.
So, let’s check the second welding method- MIG/MAG welding.
MIG/MAG welding
When welding is done in a protective environment containing inert gas, then the welding method is called MIG. And when the protective gas interacts with the metal, the welding method is called MAG.
MIG/MAG welding is done with a consumable electrode. During the welding process the welding arc ignites between the consumable electrode and the product that is being welded, and the whole process is realized again in an protective gas environment.
The protective gas that can be used in mig/mag welding is argon, carbon dioxide or other gas combination. The additional material that is used in this welding method can be with a different chemical composition depending on the metal that is going to be welded.
One of the differences between MIG and MIG/MAG welding methods is that in MIG welding the additional material is fed most often in the form of an electrode. On the other hand MIG/MAG welding works with a rolled electrode that is fed to the welding mechanism.
The other main difference is that MIG/MAG welding can be mechanical, robotized or semi-mechanical.
Working principle of MIG/MAG welding
In MIG/MAG welding method the electrical arc is ignited between the consumable electrode (rolled wire) and the welded metal. The electricity power that supplies theMIG/MAG welding machine has a high density (100 - 400 A/mm2) which creates good conditions for achieving high efficiency.
The power of electricity that supplies the welding machine is regulated with а commutator, and the wire is fed at a speed that suits the width and the type of the welded metal element.
The interesting thing about this welding method is that the consumable electrode acts both as a carrier of the electrical arc and a welding material.
Advantages of MIG/MAG welding
- with this welding method we can make ceiling and vertical welds with high quality and precision;
- the welding seams are smooth and without pores;
- by using MIG/MAG welding we can make different types of welds- spot-welding of metal elements with a different width and size (from small-size details to sheet iron with a width of more than 0,6 mm);
- The efficiency of MIG/MAG is much higher than the efficiency of MIG welding;
- During MIG/MAG welding the heating of the welded element is reduced to a minimum, which makes MIG/MAG welding suitable for welding metal details without risk of deformation.
Disadvantages:
There a re hardly any due to the fact that, regardless of the type of the welding arc, this welding method offers very good results compared to the other welding methods.
One disadvantage can be the fact that MIG/MAG welding includes a protective environment with an inert gas andthis enables factors like wind, air current and others to influence the welding process. For this reason this type of welding can be done indoors or at sheltered places
Application:
MIG/MAG welding has a wide application in literally every sphere- chemical production, machine production, car production, water-supply pipes construction, building construction and home welding tasks.
We have briefly reviewed what is MIG/MAG and MIG welding are and we hope that the information will be useful to both professional welders and those who want to specialize in welding metal constructions.
In conclusion we can say that both welding methods have their advantages and disadvantages. Both of them have a wide application in all production spheres and in everyday life.
Besides these two welding methods, several other methods also exist. One of them is ММА or the so called manual metal welding. There is also laser and robotized welding and many other methods that are used for welding special metal constructions.
Safety standards
Regardless of the chosen welding method, it’s always necessary to follow the safety standards in welding. These standards include instructions about how to weld in a right way. Welding standards include definition and rules about the different operations performed with welding machines. They include the European welding standards and safety measures that need to be followed.
The safety measures for welding operations should be followed because improper handling of welding machines is dangerous and brings risk of incidents.
The use of a special mask during welding is mandatory for the welder because the electrical arc generates powerful light and ultraviolet radiation, which can damage the eyes of the welder.
Besides with special goggles and mask, the welder needs to be also equipped with safety clothing because the process of welding generates sparks that can create burns when stuck on the welder’s skin or clothes.
Leather gloves are also necessary because of the reasons we have mentioned above.
If welding is done indoors, the place where it’s done needs to be well-ventilated, so that the smoke produced through welding flows away from the work site.
