Arc Welding: Definition, Types, and How it’s Work?

What is Arc Welding?

Arc welding is a welding process that is used to join metal to metal by using electricity to create enough heat to melt metal, and the melted metals, when cool, result in a binding of the metals. Arc welders can use either direct (DC) or alternating (AC) current, and consumable or non-consumable electrodes.

It is a type of welding that uses a welding power supply to create an electric arc between a metal stick (“electrode”) and the base material to melt the metals at the point of contact. The welding area is usually protected by some type of shielding gas, vapor, or slag.

Arc welding processes may be manual, semi-automatic, or fully automated. First developed in the late part of the 19th century, arc welding became commercially important in shipbuilding during the Second World War. Today it remains an important process for the fabrication of steel structures and vehicles.

How Does Arc welding Work?

Arc welding is a type of welding process using an electric arc to create heat to melt and join metals. A power supply creates an electric arc between a consumable or non-consumable electrode and the base material using either direct (DC) or alternating (AC) currents.

Arc welding uses an electrical arc to melt work material. First, a grounding wire is attached to the material. Next, the welder places an electrode lead against the work material.

Engineering Choice | The biggest engineering Blogs

As the welder draws the electrode away from the material, it creates an electric arc, otherwise known as an ongoing plasma discharge from the electrical breakdown of gas. Arc welders use either AC or DC power and are used to produce a very concentrated, narrow weld point.

An electric arc from an AC or DC power supply creates an intense heat of around 6500°F which melts the metal at the joint between two workpieces.

The arc can be either manually or mechanically guided along the line of the join, while the electrode either simply carries the current or conducts the current and melts into the weld pool at the same time to supply filler metal to the join.

Because the metals react chemically to oxygen and nitrogen in the air when heated to high temperatures by the arc, protective shielding gas or slag is used to minimize the contact of the molten metal with the air. Once cooled, the molten metals solidify to form a metallurgical bond.

Arc welding is a type of welding process using an electric arc to create heat to melt and join metals. A power supply creates an electric arc between a consumable or non-consumable electrode and the base material using either direct (DC) or alternating (AC) currents.
Arc welding

Types of arc welding

Arc Welding can be categorized into two different types;

Electrode consumptionWelding method
Non-consumable (non-fusible) electrode type1. TIG welding
2. Plasma welding
Consumable (fusible) electrode type1. Shielded metal arc welding
2. MAG welding
3. MIG welding
4. Electrogas arc welding (EGW)

There are different types of arc welding. Which arc welding method you use depends mostly on the metal. Following is an overview of various kinds of arc welding techniques:

Flux-cored arc welding (FCAW)

This type of arc welding uses tubular electrodes filled with flux. While emissive flux shields the arc from the air, none missive fluxes may need shielding gases. It is ideal for welding dense sections that are an inch or thicker because FCAW has a higher weld-metal deposition rate.

Gas metal arc welding (GMAW)

GMAW or MIG welding shields the arc with a gas like argon or helium or a gas mix. The electrodes have deoxidizers that prevent oxidation, so you can weld multiple layers.

This method has several benefits: simple, versatile, economical, low temperatures, and easily automated. This is a popular welding technique for thin sheets and sections.

Gas tungsten arc welding (GTAW)

GTAW or TIG welding is often considered to be the most difficult. Tungsten electrodes create the arc. Inert gases like argon or helium or a mix of the two are used to protect the shield. Filler wires add molten material if needed. This method is much “cleaner” as it doesn’t produce slag, making it ideal for welding jobs where appearance matters as well as thin materials.

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.

Shielded metal arc welding (SMAW)

SMAW is one of the simplest, oldest, and most adaptable arc welding methods, making it very popular. The arc is generated when the coated electrode tip touches the welding area and is then withdrawn to maintain the arc.

The heat melts the tip, coating, and metal so that the weld is formed once that alloy solidifies. This technique is typically used in pipeline work, shipbuilding, and construction.

Submerged arc welding (SAW)

SAW works with a granular flux that creates a thick layer during welding, which completely covers the molten metal and prevents sparks and spatters. This method enables deeper heat penetration because it acts as a thermal insulator. SAW is sued for high-speed sheet or plate steel welding. It can be semiautomatic or automatic. However, it is limited to horizontal welds.

Electro-Slag Welding (ESW)

A vertical process is used to weld thick plates (above 25mm) in a single pass. ESW relies on an electric arc to start before a flux addition extinguishes the arc. The flux melts as the wire consumable is fed into the molten pool, which creates a molten slag on top of the pool.

Heat for melting the wire and plate edges is generated through the molten slag’s resistance to the passage of the electric current. Two water-cooled copper shoes follow the process progression and prevent any molten slag from running off.

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:

  • Cost: equipment for arc welding is well-priced and affordable, and the process often requires less equipment in the first place because of the lack of gas
  • Portability: these materials are very easy to transport
  • Works on dirty metal
  • Shielding gas isn’t necessary: processes can be completed during wind or rain, and spatter isn’t a major concern
  • High Welding Speed
  • Produces Very Less Distortion
  • Less Smoke or Sparks are Involved
  • Smooth Welding is Achieved
  • Can be Carried Out in Any Atmosphere
  • Good Impact Strength
  • Higher Corrosion Resistance

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:

  • Lower efficiency more waste is generally produced during arc welding than many other types, which can increase project costs in some cases
  • High skill level operators of arc welding projects need a high level of skill and training, and not all professionals have this
  • Thin materials it can be tough to use arc welding on certain thin metals
  • Cannot be used for reactive metals like Aluminum or Titanium

FAQs

What is Arc Welding?

Arc welding is a welding process that is used to join metal to metal by using electricity to create enough heat to melt metal, and the melted metals, when cool, result in a binding of the metals. Arc welders can use either direct (DC) or alternating (AC) current, and consumable or non-consumable electrodes.

What are the types of Arc Welding?

Arc Welding can be categorized into two different types;
1. Consumable Electrode Methods
1.1 Shielded metal arc welding.
1.2 MAG welding.
1.3 MIG welding.
1.4 Electro gas arc welding (EGW)
2. Non-consumable Electrode Methods
2.1 TIG welding
2.2 Plasma welding

How Does arc welding Work?

Arc welding is a type of welding process using an electric arc to create heat to melt and join metals. A power supply creates an electric arc between a consumable or non-consumable electrode and the base material using either direct (DC) or alternating (AC) currents.