Welding is a process used to join metal parts by heating and melting the parts in contact and, in some cases, a filler metal. It has the advantage of creating an extremely strong joint when done properly.
At Omnifab, our expert welders can perform different types of welding, enabling us to tailor our welding service to the mandate and requirements of our industrial customers.
In this article, we present some of the welding techniques frequently used by our certified welders.
Shielded metal arc welding (SMAW)
Shielded Metal Arc Welding (SMAW) is a manual welding process involving the use of rods (electrodes) that are coated with a flux to deposit molten metal on metal parts.
To weld using this technique, you need a welding unit capable of creating a current (AC or DC) to form an electric arc between the electrode and the metal to be welded. Under the effect of the heat generated by the arc (approximately 3900 to 5500 degrees Celsius), the rod and metal melt. The force of the arc directs the molten filler metal into the molten pool to form the weld bead.
At the same time, the heat of the arc also melts the rod’s coating (flux), forming a layer of gas that protects the weld from certain atmospheric gases that can contaminate it and adversely affect the quality of the result.
Examples of applications for arc welding with coated electrodes
SMAW is one of the most popular welding processes in the world today, mainly because it can be used to weld and repair steel, stainless steel and cast-iron assemblies, as well as a wide range of alloys.
A good example of its use is for welding pipeline and piping systems for the petrochemical industry.
Gas metal arc welding (GMAW, MIG, MAG)
Gas metal arc welding (GMAW) is a semi-automatic welding process. In this process, the metals are melted by the heat generated by an electric arc between the parts to be joined and the electrode, which consists of a fusible metal wire.
This process is referred to as “under-gas”, as gas is continuously injected into the arc during welding to completely isolate the molten metal from the ambient air and its contaminants.
The acronyms MIG (Metal Inert Gas) and MAG (Metal Active Gas) are associated with this type of welding. The MIG process involves the injection of a neutral gas that does not react with the molten metal, while the MAG process involves the injection of a gas mixture capable of modifying the properties of the weld.
Examples of gas-arc welding applications
Gas metal arc welding is a logical choice when the aim is to achieve high output and/or thick beads.
It is therefore an ideal technique for structural steelwork and mechanically welded assemblies of all kinds.
Do you need reinforcement for a welding project?
Gas metal arc welding with tungsten electrode (GTA-W (TIG), GTAW-P)
Gas metal arc welding uses a non-consumable tungsten (or tungsten alloy) electrode protected by an inert gas, hence the acronym TIG (Tungsten Inert Gas) sometimes used.
This process also involves the use of a welding machine capable of creating an electric arc between the metal to be welded and the electrode. However, as the electrode does not melt under the effect of heat, it enables joints to be made without filler metal, which can be useful in certain circumstances. In such cases, the resulting welds have the same chemical integrity as the original base metal.
In this type of industrial welding, the molten metal, the tungsten electrode and the welding zone are protected from the ambient air by a stream of inert gas passing through the welding torch.
Examples of gas metal arc welding applications with tungsten electrode
Since TIG welding uses an infusible electrode, it is particularly effective for joining metal parts just a few millimeters thick.
It is also widely used in the food and pharmaceutical industries, since it leaves no residue and does not contaminate the base metal.
Fluxcore arc welding (FCA-W)
During the fluxcore welding process, an electric arc is used to provide the heat needed to join a filler metal electrode to the base material.
However, it’s essential to mention that this electrode is a flux-filled tube, hence the widespread name “fluxcore” welding. During soldering, the flux melts and forms a slag (molten waste) that covers and protects the solder joint from the ambient air, even in windy conditions.
The metals best suited to flux-cored arc welding are carbon steel, stainless steel and low-alloy steels, while most non-ferrous metals (such as aluminum) cannot be welded using this method.
Examples of fluxcore welding applications
Because of its high welding speed and outdoor suitability, fluxcore welding is frequently used in the construction industry.
It is also ideal for mobile welding assignments in all kinds of weather conditions.
Looking for a partner in industrial welding?
Reading this text, you may have realized just how complex a field industrial welding is. Before entrusting a welding mandate to a company, make sure that its personnel are trained and equipped to offer you the service you really need.
At Omnifab, our welders can guarantee solid, resistant and aesthetically pleasing welds, whether performed in our factory or at the location of your choice thanks to our mobile welding unit.
Contact us and we’ll propose welding solutions 100% adapted to your project.
