Did you know that welding stems from the art of metallurgy, which started around 7000 BC? Slowly the process of putting metals together evolved as technology entered the scene. This article will discuss what welding means, the different types, and which applications they’re best suited for.
What is welding?
Welding is the process of fusing metal parts at their melting point. In some instances, a filler metal is inserted during the heating process to help the metals bond together. Moreover, pressure may also be used to help the process in order to produce a weld. Welding is not as simple as brazing and soldering. It involves extreme temperatures and complex chemical processes within the machine to bond two metals together.
Majority of these welding processes require protection for the main components and filler/s from being oxidized while the process goes on. With the use of different energy sources, welding may be performed and some of those include:
- Gas flame powered by acetylene
- Electrical arc
- Electron beam
Different types of welding
The art of welding has been used in metallurgy for thousands of years. Our ancestors used metallurgy for creating goblets, forging swords, and other metal works. However, forge welding, which has been the technique blacksmiths use to join steel and iron, was the most popular. As more people experiment and try new things, various techniques surfaced during the 19th century. These include arc welding and oxy-fuel welding. Now, let’s take a further look:
MIG - Gas Metal Arc Welding (GMAW)
MIG welding is the most common type of welding for hobbyists, DIY enthusiasts, and welders on a budget wanting to save resources. It also reduces waste because of multiple eco-friendly qualities, including less fumes, easier clean-up, and increased electrode efficiency. There’s bare wire MIG welding, which is applied for thin pieces of metals, and flux core MIG welding, which doesn’t require a gas supply or flow meter, ideal for outdoor use.
There are also disadvantages to this type of welding: It needs external shielding gas, which could be expensive, especially for those who are new to the craft. It’s also not suitable for vertical welding and offers poor performance when used with thick metals.
MIG welding is common in automotives, especially when changing key parts like the catalytic converter. It provides a strong weld that withstands strong forces. Aside from being used in automotives, this may also be used in constructions, maritime industries, and robotics.
MIG welding utilizes a continuous flow of electrodes released through the welding gun’s trigger, which the operator controls. An electric arc is created in between the electrode and the base material. Then, it heats the material until it reaches its melting point, allowing the welder to join it with another metal.
To execute this type of welding, make sure to find an external shielding gas. Also, remember to adjust the power settings depending on the thickness of the metal you’re welding.
TIG - Gas Tungsten Arc Welding (GTAW)
TIG welding, also known as Heliarc welding, is the most unique, albeit more difficult to learn than the other processes. Both hands are required as one feeds the rod while the other holds the torch. The torch creates the heat and arc needed to weld metals. From the different types of welding, this is used for welding most conventional metals, such as:
- Copper alloys
- Nickel alloys
TIG welding is considered the most popular type of welding people use these days. With its notable clean weld and a high degree of purity, any person may find a hard time doing that with other welding techniques. This is mostly used with stainless steel and suitable with most metals.
Several industries use it for nonferrous metals and several applications, such as tubing, vehicles, bicycles, and the repair and maintenance of different tools. It’s best used for welding magnesium, stainless steel, and aluminum.
From the different types of welding that exist, this type may also be performed by a hobbyist or a professional. It’s good for welding thin materials such as aluminum, high-quality cleaning welds, and aesthetically pleasing weld beads. This kind of welding may also be used for many alloys.
This is not recommended for new welders as the machines don’t come cheap. Users will also need extra shielding gas and a high operator skill to get the desired results.
Stick Welding - Shielded Metal Arc Welding (SMAW)
Stick welding, more commonly known as arc welding, is an old-fashioned process of welding done manually.
It uses an electrode to bring electric current to power and produce the weld metal. The electrode is made up of a coded influx core wire. Moreover, the electric arc is made when the tip of the electrode is removed while remaining close to the metals to produce a high temperature of around 6500°F. The molten metal is shielded from the nitrogen and oxygen in the atmosphere, making it ideal for construction, steel erection, and other heavy-duty applications.
Among the types of welding machines out there, the equipment for Stick welding is one of the most affordable and lightweight. It does not require shielding gas, unlike MIG and TIG welding. Hence, it may be done under different weather conditions and works fine with rusty metals.
Unfortunately, it has lower consumable efficiency and yields a lot of waste. It also requires high operator skills since it is done manually. Mastering this welding type takes a while longer than the other techniques.
It is also not suitable for thin materials. It is not recommended for welding materials that would be exposed to severe weather since it may result in high vulnerability, porosity, cracking, and shallow penetration.
Flux Welding - Cored Arc Welding (FCAW)
Flux welding is most similar to MIG welding. Not only does this process need a continuously fed electrode but also a tube-shaped flux-filled wire.
Just remember that this technique may not appear aesthetically pleasing to most people, but many still prefer it for its easy-to-learn quality.
With the higher electrode efficiency, it produces less waste than the other welding types. It does not require external shielding gas, plus you get less welding fumes no matter what kind of metal is used for welding.
Another advantage is that it is a clean type of welding which means less debris on your end. It is also easy to learn, making it great for DIY enthusiasts or hobbyists.
On the other hand, the most common disadvantage is that it produces a lot of smoke and that the equipment for this method may be costly. It is not recommended for welding thin materials as it may produce slag.
Electron Beam Welding (EBW)
This type of welding is the most precise high-energy technique, using a ray of high-velocity electrons and materials needing welding. It transforms the energy from the electrons into sheets so that the materials melt. Therefore, letting you merge and join the materials together.
What’s unique about EBW is that it is quite precise and often repeatable since it needs automation. With its precise and accurate weld penetration control, you can make penetrations as deep as 0.0001 inches.
EBW maintains around 95% of the strength of the raw materials. Moreover, this is usually performed in a vacuum environment, which significantly reduces the impurities left by the procedure. This is the best option for sealing electrical components and pre-evacuated housings.
Oxides and nitrides are eradicated during this process while the impurities on the materials vaporize.
Lastly, it may be used on refractory materials or other metals that are not weldable using the conventional process.
The most notable disadvantage is that it needs regular maintenance and check-ups. Therefore, support may be more cost-demanding.
Atomic Hydrogen Welding (AHW)
This process uses a high-temperature form of welding, commonly known as arc-atomic welding. It needs hydrogen gas to shield two electrodes formed by tungsten. However, AHW was replaced by the gas metal arc welding technique, although some still use it for the specific purpose of welding tungsten.
Tungsten is highly resistant to heat. ABW allows you to weld it without damaging the material and still create a cohesive, strong weld. Just remember to wear protective gear.
Gas Tungsten-Arc Welding
This type of welding is considered one of the most challenging and time-consuming as there’s a minuscule area between the flame and the material to be welded. It was first used in 1941, developing new changes in the technology ever since. Moreover, it is used in manufacturing bicycles, military, and commercial aircraft.
Plasma Arc Welding
Plasma arc welding utilizes electrical current passing through a small nozzle, which goes through the protective gasses to obtain accurate results, especially in welding and joining small areas.
This is best for heating metal in very strong and extreme temperatures, yielding stronger and deeper welds. It is used in the aircraft manufacturing industry, which requires experience and skills.
The art of welding started back in the 1800s and continues to this day. Various techniques emerged and developed through the years, with some ultimately becoming obsolete. With the different metals and materials in the world, welding may be explored by hobbyists, DIY enthusiasts, and professionals.