What Is Arc Welding?

There are many ways to weld metal. But arc welding counts as one of the most common techniques, thanks to its versatility and strength. So what is arc welding?

Arc welding is a welding method that uses an electric arc. This electric arc generates intense heat, so strong that it melts and fuses materials together. Depending on the process, it can use a consumable or non-consumable electrode and run on direct (DC) or alternating (AC) current.

From precision components to industrial machinery, arc welding plays an important role in many industries. But how does it work and what are its applications? In this guide, we’ll break down everything you need to know about this welding technique.

What Is Meant by Arc Welding?

In arc welding, two pieces of metals are combined using concentrated heat from an electronic phenomenon. This process is called an “electric arc”. It occurs when a positive voltage is applied to the electrode and negative voltage applied to the base material. The electric arc is supplied by an AC or DC power supply. It can reach very high temperatures, well beyond 3,000 degrees Celsius.

Typically, two metal pieces are melted and fused together. One of the materials, called a “filler material”, comes from a consumable electrode applied automatically with a machine or manually. The other is the base material. A protective shielding gas or slag is used while welding to protect the molten metal from coming into direct contact with air.

What Are the 4 Types of Arc Welding?

There are different types of arc welding processes that you can choose between. It all depends on your usage case and external factors. We’ve listed the 4 most frequent types of arc welding below.

Stick Welding (SMAW – Shielded Metal Arc Welding)

Stick welding uses a hand-held electrode, where the arc forms between the metal rod and the workpiece. As both melt, they create a weld pool. A flux coating on the rod releases gas and forms a slag that protects the weld from air contamination. As the weld cools, the slag hardens on top and needs to be chipped away to reveal the final joint.

This welding method is often used for outdoor and heavy-duty work, as it doesn’t need an external gas supply and holds up well in tougher conditions.

MIG Welding (GMAW – Gas Metal Arc Welding)

MIG welding joins together two metals using a consumable and continuous wire electrode. This consumable electrode acts as both the electrode and filler metal. The wire is fed through a machine and moves continuously toward the weld joint. Consequently, it forms an electric arc between the wire and base metal that generates heat. A protective gas, such as argon, is used to keep the weld area from contaminations.

TIG Welding (GTAW – Gas Tungsten Arc Welding)

TIG welding uses a non-consumable tungsten electrode. The tungsten electrode remains solid and can resist extremely high melting points. The electrode generates the heat necessary to create the arc and can be adjusted using a foot pedal or a thumb wheel on the torch. Similar to MIG, TIG welding uses shielding gas that flows around the arc and molten metal to protect it from contamination by airborne impurities.

TIG welding can be performed autogenously (without filler) or with the addition of a filler rod. When filler is required, a separate filler rod is manually fed into the weld pool. But if no filler is needed, the process simply fuses the base metals together.

Flux-Cored Welding (FCAW – Flux-Cored Arc Welding)

Flux-cored arc welding (FCAW) uses a continuously fed wire electrode that melts in the electric arc to join metals. The wire has a flux-filled core which releases a protective shielding gas when heated. This eliminates or reduces the need for an external gas supply. As a result, FCAW is well-suited for outdoor, high-production, and heavy-duty welding applications.

How Is Arc Welding Different From Normal Welding?

The term "arc welding" and "normal welding" can feel like it's interchangeable. But in reality, there are big differences.

The main difference is that arc welding is a welding technique that uses an electric arc. This arc generates the heat needed to melt and join two metals together. Whereas, the term “normal welding” is broader. It can refer to any type of welding method, from laser welding, gas welding to arc welding.

What Are the Advantages of Arc Welding?

So what makes arc welding stand out compared to welding techniques? Its main advantage lies in its cost-effectiveness. Firstly, the equipment is relatively affordable. For instance, some methods, like stick welding, don’t require an external gas supply. But many arc welding methods also require minimal equipment. So it’s a relatively practical choice for both indoor and outdoor welding.

Arc welding isn’t just cost-effective - it’s also versatile and durable. It works on a variety of metals, including steel, stainless steel, and cast iron. The result is strong, deep-penetration welds that hold up under heavy stress.

What Are the Disadvantages of Arc Welding?

Like any process, arc welding has its downsides that you should consider.

The major drawbacks is it requires a higher level of skill and training for arc welding to do the work properly. Not all methods are far, nor cost-effective or suitable for large scale production. For example, some processes produce excess spatter, requiring additional cleanup which can slow down the workflow.

Frequently Asked Questions

Is Arc Welding AC or DC?

Both alternating current (AC) and direct current (DC) can be used in arc welding. DC is used in MIG, TIG and Stick welding for most materials. Meanwhile, AC is used when welding aluminium and magnetized materials, as it helps to break down the oxidation layers.

Is Arc Welding the Same as MIG?

No, Arc welding is a broader category that includes different electric arc methods. Of which MIG welding is just one type of arc welding.

Conclusion: What Is Arc Welding?

Arc welding is a welding process that relies on an electric arc that generates intense heat to fuse metals together. It’s a broader term that includes various methods, from MIG, TIG, Stick to Flux-Covered weldings and other. Whereby each method is suited for different materials, environments and production needs.

We hope that this article has helped you better understand the arc welding processes, and the different choices of methods that you can use in your project. If you’re looking for arc welding services, sign up at Haizol and submit a free request for quotation to receive same-day quotes from multiple factories.

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