Welding is a process that joins pieces of metal together by melting their ends at high temperatures and fusing them. The resulting bond is called a weld. There are four different welding procedures that commercial welding services provide.
This blog article will look into these welding procedures, how they are performed, the equipment required, and their pros and cons.
Outline:
- Shielded Metal Arc Welding (SMAW)
- Flux Cored Arc Welding (FCAW)
- Gas Tungsten Arc Welding (GTAW)
- Gas Metal Arc Welding (GMAW)
- Conclusion
1. Shielded Metal Arc Welding (SMAW)
Commonly referred to as stick welding, this type of welding uses a hollow electrode.
The welding rod is made from stainless steel or other material such as copper alloy that melts at lower temperatures. It is connected to an electrode holder, which acts as an electrical clamp.
The setup allows electricity to flow from the welder up through the rod.
Meanwhile, you put the other clamp on the welding table or the part you’re working on to complete the circuit.
Touching the end of the rod to any metal will make a short circuit and a spark that starts an arc. An arc is where electricity jumps over a gap, creating tremendous heat.
This phenomenon allows it to melt the base metal and the center of the welding rod, which then merges after cooling.
The stick-like rod protects the molten pool from contamination by the oxygen in the air by covering it with a coating made from flux-cored wire.
Because it can support itself while still penetrating the joint welded, the same wire can be utilized for fillet and groove welds. Thus, you don't have to worry about backing up or cleaning off your work after each pass.
Pros
- Stick welding has affordable equipment, and many models are portable
- Ideal for general purpose work and structural projects such as welding furniture, smoker, or even trailers
Cons
- Slag coating remains after welding, which needs to be cleaned by tools such as a chipping hammer
- It can’t be used to weld thin metal sheets since there’s a risk of burning through the material.
2. Flux Cored Arc Welding (FCAW)
Flux-cored arc welding is used for most metals. It's a relatively simple process that uses the heat from a small electrode to melt a wire coated with flux.
However, instead of an electrode rod, it uses a winded welding wire fed into a motor to push it into the weld gun automatically.
The electrode melts the wire and produces an arc that fuses the materials. The weld pool is created when the molten metal touches the surface of the workpiece being welded.
This type of welding involves two separate processes- the use of self-shielding agents created when the wire’s fluxing agents decompose and shielding gas.
FCAW also allows welders to do their welding outdoors and much of the portable equipment. It is used in manufacturing, construction, and automotive repair.
Pros
- Easier to use because you won’t have to worry about striking an arc
- Can make continuous welds since you won’t efficiently run out of an electrode
Cons
- Much like stick welding, you also have to clean up the slag
- It’s a bit more expensive because of the added equipment
3. Gas Tungsten Arc Welding (GTAW)
Gas Tungsten Arc Welding (GTAW) is a type of welding that uses a non-consumable tungsten electrode to create the arc. Tungsten is a metal that doesn’t quickly melt even at extreme temperatures and is commonly found in incandescent bulbs.
The weld pool is formed by the filler wire, which melts and flows into the joint. The filler rod can be made up of many different metals, depending on what kind of weld you are trying to create.
Tungsten’s excellent heat resistance lets you create an arc and focus the heat on one spot. You can decouple that by adding metal to it. Because of this unique setting, the welder can have excellent control and create precise welds.
GTAW also uses an inert shielding gas, such as argon or helium, to protect the weld pool from contamination by oxygen in the air. It also helps keep moisture out of the pool so that it doesn't cause hydrogen embrittlement in your steel parts.
This type of welding is popular on objects needing small-diameter, thin-wall tubing like those found in bicycles. It’s also used in metals such as copper, magnesium, and aluminum.
Pros
- It does not have a metal spatter since there’s no metal transfer using the arc
- Produces high-quality welds to dissimilar metals and alloys such as aluminum with steel
Cons
- The burner’s design makes it harder to weld at an acute angle
- Metal needs better preparation compared with manual metal arc (MMA)
4. Gas Metal Arc Welding (GMAW)
More commonly known as Metal Inert Gas (MIG), this type of welding also uses a thin wire electrode. GMAW doesn’t leave any slag coating because it doesn’t use flux, unlike other welding procedures.
This welding process takes less time as you don’t have to clean the weld of any slag.
The rolled stainless steel wire is covered with copper to prevent corrosion. The wire is also fed into a welding gun, much like flux welding.
However, the welding gun has an additional nozzle outside where the shielding gas is emitted. A gas cylinder supplies carbon dioxide, helium, or argon, protecting the weld pool.
GMAW is excellent for welding thin sheet metal, construction, and auto body work. It’s also used on metals such as aluminum, nickel, copper, stainless steel, carbon steel, etc.
Pros
- One electrode size can be used on f materials with varying thickness compared to GTAW and SMAW
- Easier to master and requires fewer practice sessions
Cons
- It’s more costly than other welding methods because of the shielding gas
- The additional gas cylinders limit the portability of the whole setup
Conclusion
Many welding and fabrication companies offer these four procedures in their commercial welding services. However, not every company has the right combination of experienced welders and reliable equipment like Superior Welding & Fabrication, LLC.
To schedule an appointment or receive a quote, contact our hotline immediately. You can also visit our office to discuss your welding job in detail.