Welding is a process in which different kinds of metals are fabricated and sculpted to form a particular shape. It is a very important field for those professionals and enthusiasts who daily deal with different types of metal joining, maintenance and many other metal melting or joining task. There are various types of welding processes and each of those is unique and special. It is vital for a welder to know the various types of welding methods in order to buy a welding machine as well as in doing the weld. Here we will provide some information about the most common four types of welding methods along with some of the advantages and limitations of each. The mostly used four arc welding processes are MIG, flux-cored, TIG and Stick welding.
MIG welding is one of the most popular welding methods and commonly known as Gas metal arc welding or GMAW. This type of welding is used in welding wide varieties of metals and alloys such as magnesium, steel, stainless steel, nickel, copper, aluminum, bronze and many other nonferrous metals. In this welding process, a solid wire electrode is continuously fed through a welding gun, feeding throughout the consumable electrode. During this process, an electric arc is formed between base material and the electrode, heating up the bases and finally causing the material to melt and join. Here, a shielding gas is externally supplied, which protects the weld from nitrites or oxides present in the atmosphere that can contaminate the weld. The most commonly used gas for GMAW is carbon dioxide or sometimes a mixture of inert gas argon along with carbon dioxide. MIG welding is applicable for auto body workshops, small or large manufacturing industries and fabrication purposes.
- It is the easiest welding method and best for the entry level welders or beginners who are new to the welding field.
- Higher efficiency of electrode and high speed weld, which results in lesser waste of material parts and greater quality weld.
- Very less weld cleanup, which is user convenient and time saving.
- Lower heat input requirement, which makes the welding machine need less input power to accomplish the work.
- Minimum welding fumes, due to which least amount of fumes is released during weld, making it a better welding process.
- Its most important drawback is that an external shielding gas is required for this welding process, which adds a lifetime expense on buying gas.
- The materials to be welded should be extremely clean and free from and dust and dirt, which can cost extra time on cleaning up the materials before use.
- The welding tools are available at higher rate and also the gas requirement makes this process a costly welding method.
- MIG welding can be done at a limited position and doesn’t allow welding overhead or vertically, making the weld limited too.
- MIG welding is limited to thinner materials and it is not applicable for thicker ones.
Flux-cored arc welding or the FCAW is similar to that of MIG welding. It is used to weld various types of low and mild alloys such as steel and stainless steel, high nickel alloys and surfacing alloys. In this welding process too, the electrode is fed continuously, but through a tubular wire that has been filled with flux instead of solid wire unlike that of MIG welding. Flux-cored welding offers two welding processes; one is dual shield flux-cored welding, in which an externally supplied gas is used along with the electrode in shielding the molten weld puddle; and the other one is self-shielding flux-cored welding, in which no external gas is necessary to protect the weld. The self-shielding flux-cored process is ideal for outdoor applications during even windy conditions, as the wires form slag, which covers over the weld. For the dual shield, carbon dioxide or mixture of argon and carbon dioxide is used. FCAW is used for various heavy duty welding fields such as steel erection and heavy equipment repairing and constructions.
- The most important benefit of FCAW is that it offers two welding options, gas-shielded as well as self-shielded. If the welder doesn’t want to use gas, then the welding can also be done without any external gas requirement.
- FCAW is also good for outdoor applications, which makes this process one of the most versatile welding processes.
- It offers high electrode efficiency and minimum waste of the materials being welded, in a very low heat input requirement.
- Flux-cored welding produces least amount of fumes during welding.
- For user convenience, welding done by flux-cored needs very less clean up.
- The basic limitation of a flux-cored welding process is that a lot of slag is produced during the weld, which can highly affect the weld quality.
- Much smoke is generated during FCAW, which can make it difficult for the welder to see through and also suffocate the welder in some cases if respiratory equipment is not worn.
- Flux-cored welding is a high quality welding and the various equipments required for this type of welding can be costly enough.
- This type of welding is recommended only for welding thicker materials and it is not applicable for welding thin materials.
TIG welding is another name for Gas tungsten arc welding or GTAW. TIG welding is used in welding alloys of metals such as stainless steel, aluminum, copper and magnesium. In this process, tungsten electrode that is not consumable is used in heating up of the metal base and creating a molten weld puddle on it. With this welding process, either an autogenous metal can be created simply by melting two types of metals together or extra metal filler can be added in the molten weld puddle in order to enhance the properties. TIG welding is like the MIG welding, and needs external gas supply for shielding the puddle. Argon is mostly used in TIG welding, but for heavy aluminum weld, mixture of argon and helium can be used. TGAW is applicable for various high quality welding fields like manufacturing and repairing bikes, piping systems and aerospace welding.
- TIG welding offers not only high quality welds, but also very clean weld and free of spatter.
- TIG welding can be used in welding wide range of alloys.
- With this process, the thinnest materials can be welded.
- In this type of welding, the welder has tremendous control over the weld and welding can be much more accurate.
- The weld beads formed by this welding process are highly aesthetic.
- The most important limitation of TIG welding is that, for this type of welding, the materials to be welded should be clean and free from dirt. Extra pre-welding clean up can be very much time consuming.
- TIG welding is not possible without external inert gas supply, which adds a lifetime expense.
- The equipments required for this process is comparatively pricey.
- TIG welding is much more complicated and hard to master. For this type of welding, the welder must be highly skilled.
- The deposition rate is much low when compared to other welding types.
Stick welding is another name for shielded metal arc welding or SMAW. This type of welding is used for welding almost all the ferrous metals and also other metal types, using special electrode. In this process, a welding rod or electrode, consisting of a flux coated core wire, is used to carry the current, providing the majority of the metal weld. When the electrode is held close to the metal piece after its tip touches it and high heat energy is formed, it heats and melts both the electrode and metal base and creates the weld. As the flux coating vaporizes, it forms a layer of gas that protects the weld from any kind of contamination, due to which a slag is formed after the weld is done. Stick welding is used in fields like heavy equipment repairing, construction, pipeline welding and many more.
- Stick welding has the best advantage as it is applicable even at windy or rainy situations.
- The equipments required for this type of welding are very low priced and highly affordable.
- It requires no external shielding gas supply and cuts the extra expense.
- No matter how dirty or dusty the piece of metal to be welded is, stick welding needs no such pre-welding clean ups, which saves a lot of time.
- The welding speed is very slow when compared to other welding types.
- It is a complex welding process and the welder needs to be skilled for this type of welding.
- Slag is formed on each weld and it needs to be chipped away after the weld, which can be a very much time consuming task.
- Stick welding is difficult when applied for thinner materials.
- The welding rods need to be replaced most frequently, in comparison to other welding types.
There are many more welding methods, from simple flame welding to other high quality welding like laser beam welding, but those four are the mostly used welding procedures by trained welders, who deal with daily welding. Knowing the different welding processes not only provides certain knowledge about welding, but if will also help you in choosing the right welding machine, in case you are planning to get a new one.