Mig Vs Arc Welding: When To Use What, Comparative Analysis On Different Factors

This article discusses about the topic mig vs arc welding. Welding is a fabrication technique in which two or more metals are joined together with the help of heat and pressure.

Different sources of heat provide different amount of heat at the joint. Different amount of heat and pressure will result in welds of different properties. In this article we shall focus on two kinds of welding namely mig welding and arc welding. Let us start our discussion with the definition of welding.

What is welding?

Welding is a fabrication technique used to join two or more metals. This is done with the help of heat and pressure. An optimum amount of both these parameters are needed to provide the weld of desired properties.

If any one of the parameters is not properly regulated then the weld formation will not take place properly and the weld may break due to weakness. Different applications require different types of weld properties, so the sources of heat may be changes in order to make the welding process economical and energy saving.

What is mig welding ?

Mig welding stands for Metal inert gas welding. As the name suggests, this type of welding includes the participation of inert gas like Helium.

Helium protects the weld pool and the bare wire electrode. The welding takes place as a result of arc striking the surface of the work piece. The tip of the electrode is the place where arc takes place. The arc generates enough heat to create a weld pool in the surrounding area. A weld bead is formed which is allowed to cool at room temperature. This weld bead is the desired joint.

Image credits : Weldscientist, RK WL GMAW, CC BY-SA 4.0

What is Arc welding?

Arc welding as the name suggests uses an arc to fulfil the purpose of welding. The arc is generated by an AC or DC supply. A consumable or non consumable electrode can be used in this process.

There are four types of arc welding which are been discussed in the later section of this article. The heat generated from the arc is used to join the two metals. An arc is formed when there is high voltage passing through the electrode and the electrode is lifted by a very small distance from the work piece disconnecting the circuit. The arc flows through this short distance.

Mig vs arc welding strength

The strength of welds are different for different welding processes. The table below shows the difference between mig welding and arc welding strength.

Mig welding	Arc welding
The welding is stronger on thinner materials	The welding is weaker for thinner materials
The welding is weaker on thick materials	The welding is stronger for thick materials

Gasless mig vs arc welding

The comparison between gasless mig vs arc welding is given in the table below

Gasless mig welding	Arc welding
No gas is required for shielding	No shielding is required
Better for both thin and thick sheets of metals	Better for thick sheets for metals
The set up is expensive	The set up is cheaper than gasless mig

Submerged arc welding vs mig welding

The comparison between submerged arc welding and metal inert gas welding is shown in the table below

Submerged Arc welding	Mig welding
Uses continuous feed wire	Uses continuous feed wire
Uses powdered flux for shielding	Uses inert gases like Helium for shielding
Fully automatic	Semi automatic
Used for only down handing welding	It can be used in various positions
Used for very thick metals	Used for thin plates.

Spray arc welding vs mig

Spray arc welding	Mig welding
Molten metal droplets are transferred through the arc	Only electric spark is passed through the gap between electrode and the surface of workpiece
Used for thicker metals or butt joints	Used for thin metal sheets

Shielded metal arc welding vs mig

Shielded metal arc welding	Mig welding
Conventional arc welding process which uses a flux to shield the weld.	A continuous wire is fed to the work piece. A spark between the tip of the wire and workpiece melts the wire and makes a weld pool
Manually operated	Semi automatic
The coating of the electrodes evaporates that acts as shielding gas	Inert gases like Helium is used for shielding

Mig welding vs electric arc welding

Mig welding	Electric arc welding
Continuous wire is fed to the work piece	A stick electrode is used for welding process
Works on thinner materials	Works on thicker materials
Uses inert gases for shielding	Uses the evaporated electrode coating for shielding purposes.

Is arc welding better than mig?

The answer to this question depends upon the type of application required. Both of these welding techniques are good for their respective application requirements.

If we want to weld thinner metals than mig welding is suitable as it gives a good finish for thin sheets of metals. When the metal is thick than a good weld will be formed when we use arc welding. Mig is not as effective on thicker metals as arc welding.

Sources of heat in welding

The following list shows the sources of heat in welding processes

• Arc– Arc is formed when a high amount of voltage is passed through the electrode when it is in contact with the work piece. The electrode is lifted by a very small amount such that a small gap is created. Due to high voltage the electrons jump from the electrode to the surface of the work piece. This is called as an electric arc.
• Plasma– Plasma is nothing but an electrically charged gas. This electrically charged gas particles produce enough heat on the surface of work piece that it can be used for welding
• Torch– A torch is simply a flame throwing device with a nozzle through which flame comes out. The high temperature flame is directed towards the area where welding needs to be done.
• Laser– The energy from lasers heat up the surface of work piece. The lasers produce a very high temperature at the surface of the work piece.
• Electron beam– Electron beams can be directed to the work piece to provide heat energy at the surface. The electron beam is converged to a single point using deflecting apparatus.