When people ask the question “What is welding?” They are often surprised at the complexity of the answer. Welding is a complex topic to explore, but at the very basic level, it can be best understood as a process that joins two metal parts together. In this beginner’s guide, we will take a closer look at welding, the different welding methods, and some of the advantages and disadvantages of this process.
What is Welding?– Ten Fundamental Welding Principles
Welding is a fabrication process that uses heat or pressure or both to fuse two different metallic surfaces together. This is a construction adjacent activity that is widely used and there are ten fundamental welding principles that further define this process. They are:
1/ Welding is primarily used to fuse metals together, but it can be used to fuse other materials, including wood and thermoplastic components.
2/ A welded joint is referred to as a weldment or a weld joint.
3/ Different metal surfaces will react in different ways depending on their chemical, mechanical and physical properties.
4/ Applying heat to the surface can alter the malleability, ductility, and ultimately the strength of the metal. When wood is welded the process can straighten warping if sufficient heat is applied.
5/ The welding process requires a working knowledge of chemistry, physics, and metallurgy and a considerable level of practical skill.
6/ The parts that are fused are referred to as the “parent material” and the material used for the weldment is known as the “filler material”.
7/ The welding process bonds two materials of the same type together using pressure welding, heat welding, or a combination of both types.
8/ If too much heat is applied to metal, it can alter the crystalline structure which will weaken the material.
9/ During the welding process, the metal is heated and cooled and no additional chemical reaction takes place. But, if an interaction between molten metal and oxygen occurs the resulting weld joint will be weaker. During welding, protective gases are pooled around the working area to prevent contamination.
10/ A welder can add extra metal to make the weld joint stronger.
The Types of Welding
As we mentioned earlier, the exact welding process that’s used to fuse two materials together will be determined by the needs of that material. Anyone that wants to learn to weld or needs to improve their welding skills needs to understand these different processes. Let’s take a look at six of the most popular welding processes in more detail. They are:
1. Gas Metal Arc Welding (GMAW)
When people ask “What is welding?” this particular process is probably what they have seen in movies and TV shows. This process is also known as Metal Inert Gas (MIG) welding and it’s widely used in the automotive industry, construction, and manufacturing processes. A welding gun with an electrode wire creates an electric arc for the heat and a gas shield is projected to protect the welding joint. This welding process is popular because it’s simple, efficient, and cost-effective
2. Shielded Metal Arc Welding (SMAW)
This welding process is also widely known as “Stick Welding” and it uses special welding sticks or rods. These rods are the filler material mixed with flux which facilitates the welding process and protects the weld joint. This process is used in field repairs, mining, aerospace, construction, and shipbuilding. Stick welding is an attractive option because it’s accurate, strong, and very affordable.
3. Tungsten Inert Gas (TIG) Welding
This is one of the most popular welding processes because the created weld joint is very smooth, clean, and superior in quality to many alternatives. TIG welding uses a non-consumable tungsten electrode to produce the required heating arc. This type of welding is widely used in the automotive industry, aerospace, and metallic art sculptures.
4. Flux-Cored Arc Welding (FCAW)
This is a similar process to the MIG welding process outlined above. Welders like to use FCAW for general repairs and welding outdoors because it’s easy to use. The primary difference between FCAW and MIG welding is that the former uses a tube-shaped filler wire which contains the flux material. Some typical applications for this welding process include manufacturing, pipeline repairs, shipbuilding, industrial welding, and fabrication.
5. Submerged Arc Welding (SAW)
This welding process used flux, but it’s very different from FCAW. The welding takes place under a granular flux blanket which prevents exposure to ultraviolet light and fewer welding fumes are created. This is regarded as one of the safest welding processes and it’s the preferred method for manufacturing processes, structural construction, and shipbuilding.
6. Hyperbaric Welding
This is the welding process that’s used underwater, it’s similar to stick welding, but the flux creates bubbles of gas that shield the welder from the risk of electrocution.
Other Welding Processes
These are the most common welding processes, but there are many more that are beyond the scope of this beginner’s guide, including plasma arc, electrogas, electroslag, atomic hydrogen (AHW), energy beam (EBW), oxyacetylene (gas), electron beam, spot, seam, solvent, resistance, braze, electron beam, laser beam, carbon arc (CAW) and many other more extreme fusing methods.
Why is Welding Important?
Welding creates a permanent weld joint to fuse two materials together and it’s one of the most efficient methods that’s used to speed up fabrication times. As a process, welding is extremely flexible and versatile for indoors and outdoors use. When the right filler material is used, the strength and durability of the weld joint may even outlast the rest of the material.
A skilled welder using the appropriate welding process can produce clean and smooth weld joints that will not diminish the aesthetic appeal. Welding is an economically viable approach in terms of equipment, materials, and fabrication costs.
Advantages of Welding:
- Different materials can be welded together.
- The weld joint may have improved strength over the parent metal.
- Weld joint will be completely rigid which adds extra strength to the overall construction.
- Adding and modifying structures is simple.
- The weld joint can be created in any shape or direction needed,
- Welding can be performed in any location with some basic safety considerations.
- Weld joints can be clean and smooth.
- The welding process can be automated.
Disadvantages of Welding:
- Initial costs of training and purchasing the equipment can be high.
- The weld joint is permanent, the only way to dismantle the joint is to break the weld apart.
- Uneven heating and cooling can distort materials.
Conclusion-What is Welding
Hopefully, we’ve answered the “What is welding?” question to give you a brief taste of what welding has to offer. The learning curve for welding can be very steep, but it is rewarding and mastering the processes takes some time. Most welders specialize in one or two welding processes in fields that they work in regularly. Mastering multiple welding processes is certainly possible, but most people tend to stick with the methods they prefer.