What Is Arc Welding?- Types, And How Does It Work

Modern welders are a demanding group in today’s culture. Various factories and work environments require the help of welders to build, repair, and fix numerous types of machinery and complete metal fabrication projects.

The welding process is not easily taught and demands a lot of knowledge and hard work to do daily.

Arc Welding is a difficult skill for many to grasp but can be incredibly useful when learned.

This article will teach you the basics of arc welding, its advantages and disadvantages, and the different types that exist.

What Is Arc Welding?

Arc welding is a welding process used to join metal to metal by using electricity to generate enough heat to melt metal and the melted metals, when cooled, resulting in a joint of the metals.

It is a type of welding that uses a welding power supply to create an arc between a metal stick (“electrode”) and the base material to melt the metals at the point of contact. Arc welders can use either direct current (DC) or alternating current (AC) and consumable or non-consumable electrodes.

The welding area is usually protected by some type of shielding gas, vapor, or slag. Arc welding processes can be manual, semi-automatic, or fully automatic.

Arc welding was developed in the late 19th century and gained commercial importance in shipbuilding during World War II. Today it remains an important process for the manufacture of steel structures and vehicles.

Related: What is Welding?

How Does Arc Welding Work?

Arc welding uses an electric arc to generate heat and join together two metals. The power supplied to the electric arc can be alternating current (AC) or direct current (DC).

DC arc welders offer a smoother arc that works better on thin materials but are more expensive than AC arc welders.

All arc welding uses an electric arc to weld and uses the following materials:

• An electrode
• An electrode cable
• A work cable and clamp
• Power supply
• Metals to join
• An arc

Arc welding uses two types of metal:

• Parent material: These are the metal parts that are joined together during the welding process.
• Consumable material: These are the additional materials that are heated up in the arc and deposited over the joints to create a stronger bond.

In a basic arc welding process, the power supply is switched on, and the electrode is brought near the base material. Then, intense heat is generated to produce the electric arc.

This heat melts the base metal, electrode core, and flux coating. The flux coating provides a shielding environment to weld.

The molten metal is deposited between the two metalwork pieces to join them together. Once it solidifies, it forms a strong bond between the two materials. The metal workpieces are then left to cool down.

What Is Arc Welding Used For?

The most common and simplest form of welding is arc welding, so it is used across all industry sectors, including the automotive, aerospace, oil and gas, manufacturing, power, and construction sectors.

Arc welding can be used to build vessels, pressurized vessels, pipes, tanks, ships, bridges, railroads, automobiles, farm equipment, metal art sculptures, trailers, and more.

Consumable Vs. Non-Consumable Arc Welding

The electrodes (or “sticks” or “rods”) used in arc welding can be either consumable or non-consumable.

A consumable electrode not only conducts the current but also supplies filler metal to the joint. This means the electrode is made of a type of metal that melts along with the metals being welded together. This type of welding is often used in the manufacture of steel products.

A non-consumable electrode, on the other hand, is made of material that is not melted during the weld, such as tungsten, which has an extremely high melting point.

Related: What is Welding Electrode?

Arc Welding can be categorized into two different types;

Electrode consumption	Welding method
Non-consumable (non-fusible) electrode type	1. TIG welding 2. Plasma welding
Consumable (fusible) electrode type	1. Shielded metal arc welding 2. MAG welding 3. MIG welding 4. Electrogas arc welding (EGW)

Types Of Arc Welding

The different types of arc welding are roughly divided into the non-consumable electrode and consumable electrode types, as well as the arc generation and welding principles.

#1. Flux-Cored Arc Welding (FCAW)

A similar process to MIG welding, but instead of shielding gas, it often uses a flux-filled hollow electrode wire. However, non-emissive fluxes may need shielding gas.

There are two types of flux-cored arc welding:

• Self-shielded – relies on the gaseous protection from the flux-cored electrode and the slag system to shield the molten metal from the atmosphere.
• Gas-shielded – uses external shielding gas and the slag system to protect the arc from oxidation.

This method is ideal for thicker joints due to the high weld-metal deposition rate, strong weld penetration, and constant voltage welding power supply.

Common uses for flux-cored arc welding include manufacturing plants, bridge construction, heavy equipment repair, industrial piping, and railroads.

It has a flexible torch movement and orientation, making it easy for users. However, the weld isn’t usually visually pleasing. It can cause slag inclusion (the result of molten flux getting trapped inside weld) and is costlier due to the equipment needed.

#2. Gas Metal Arc Welding (GMAW).

Also known as Metal Inert Gas (MIG) welding, this process is similar to the flux-cored arc welding process since it uses a metal wire as the filler material and the electrode.

The wire creates an electrical arc that comes into contact with the workpiece and melts both materials together.

The GMAW is a high-speed process that is easier to learn than, say, TIG welding. It is reliable for welding carbon steel, aluminum, and titanium metals.

#3. Gas Tungsten Arc Welding (GTAW).

This method uses a non-consumable tungsten electrode and constant current power source to create a plasma arc between metals and can be conducted with or without filler material. Inert shielding gas protects the weld area and electrode from the atmosphere.

TIG welding can be difficult to learn and technically demanding. It requires more operator control than similar processes, but there are both manual and automatic methods available.

The process produces high-quality, clean, and strong welds but can be time-consuming. It’s primarily suitable for welding thin materials and non-ferrous metals but isn’t ideal for thicker metal joints.

#4. Plasma Arc Welding (PAW).

This arc welding technique uses ionized gases and electrodes that create hot plasma jets aimed at the welding area.

As the jets are extremely hot, this method is for narrow and deep welds. Plasma arc welding (PAW) is also good for increasing welding speeds.

#5. Shielded Metal Arc Welding (SMAW).

Shielded metal arc welding is also known as manual metal arc welding (MMA or MMAW), flux-shielded arc welding, or stick welding.

During this process, the arc is struck between the electrode flux-coated metal rod and the workpiece, and both the rod and workpiece surface melt to form a weld pool.

Simultaneous melting of the flux coating on the rod will form gas and slag, which protect the weld pool from the surrounding atmosphere. This is a versatile process that is ideal for joining ferrous and non-ferrous materials with a range of material thicknesses in all positions.

#6. Submerged Arc Welding (SAW).

Submerged arc welding is a frequently used process with a continuously fed consumable electrode and a blanket of fusible flux that biomes conductive when molten.

This provides a current path between the part and the electrode. The flux also helps prevent splatter and sparks while suppressing fumes and ultraviolet radiation.

#7. Electro-Slag Welding (ESW).

This method is a combination of arc welding and resistance welding. A wire is fed into the welding area, and flux is added to the electrical arc until the molten slag covering on the weld surface reaches the electrode and ignites the arc.

The electric resistance from the molten slag melts the filler metal and creates a molten pool on the joint surface.

Electroslag welding is ideal for welding thick materials, such as low carbon steel, due to a large amount of heat. The welder performs this process in a vertical – or close to vertical – position.

#8. Atomic Hydrogen Welding.

This arc welding process uses two tungsten metal electrodes within a hydrogen atmosphere. The electric arc breaks up the hydrogen molecules in the process and combines them again through extreme heat.

This process produces one of the hottest flames, between 3400 and 4000°C . That heat is hot enough to melt through tungsten.

Like carbon arc welding, this is another process that many welders consider outdated.

#9. Carbon Arc Welding.

During carbon arc welding (CAW), the oldest welding process, an electric arc is formed between a non-consumable carbon electrode and the workpiece, joining the metals and creating a solid bond.

The use of this welding process has decreased because of the enhanced safety and convenience of modern welding techniques.

Rod Types

The arc process uses a variety of rods that have different strengths, weaknesses, and uses which can impact weld quality. The rod is connected to the welding machine and a current is passed through to join workpieces together.

In some cases, such as with SMAW, the rods melt to become part of the weld – these are consumable electrodes. In other instances, such as with TIG, the rods do not melt – these are non-consumable electrodes.

Rods are generally coated, although the exact type of coating varies. While uncoated rods are available, these are far less common, create more spatter, and can make it difficult to control the arc.

Coated rods are better to reduce or eliminate contaminating oxides or Sulphur. The three types of coating include cellulose, minerals. or a combination of the two.

Whether coated or uncoated, the correct rod needs to be selected to create clean, strong welds with the right bead quality.

Application Of Arc Welding

The applications of Arc Welding include the following.

• Used in the welding’s of sheet metals
• For welding thin, ferrous & non-ferrous metals
• Used to design pressure & pressure vessels
• The developments of piping in industries
• Used in the domains of automotive and home furnishing
• Industries of Shipbuilding
• Used in the manufacturer of aircraft & aerospace, Auto body restorations, Railroads.
• Industries like construction, automotive, mechanical, etc.
• Gas Tungsten Arc Welding is used in aerospace industries to connect many areas like sheet metals.
• These welding are used for repairing dies, tools, and mostly on metals that are made with magnesium & aluminum.
• Most of the fabrication industries use GTAW to weld thin workpieces, particularly nonferrous metals.
• GTAW welding’s are used where extreme resistance to corrosion as well as cracking over a long period of qualities are required.
• It is used in space vehicles manufacturing.
• Used to weld small-diameter parts, thin wall tubing, making it applicable in bicycle industries.

Advantages Of Arc Welding

There are a number of advantages to using arc welding compared with many other formats:

• It is suitable for high-speed welds.
• It is a simple welding apparatus.
• It can work on AC or DC.
• Superior temperatures.
• Less smoke or sparks are involved.
• Portability as a result of the simple equipment.
• It is a fast-welding process when compared to others,
• It offers strong joints.
• Produces very little distortion.
• High corrosion resistance.
• It has the ability to weld on porous and dirty metal.
• It is the equipment that is inexpensive.
• Its operation can be performed during wind or rain.
• Its power supply can be used where there is electricity and the alternative can use be if there is no electricity but generators.
• Smooth welding is achieved.
• It is a good impact strength.
• Arc welding beads can be used to create designed on fine metals.
• It can be carried out in any atmosphere.

Disadvantages Of Arc Welding

There are a few reasons why some people look to other options beyond arc welding for certain kinds of projects. These downsides can include:

• Require skilled welders.
• Cannot be used for reactive metal like AI or Ti.
• Not suitable for welding thin metals.
• Not all thin metal can weld on arc welding.
• Well trained and skillful operator is needed for the task.
• Increases of project costs as wastage is inevitable during the process.

FAQs.