From airplanes, cars, and buildings to pipes, machinery, and household appliances, many of the everyday items we use require welding in some form or fashion. Put simply, welding is the process by which individual pieces of metal are fused together. While there are a variety of welding techniques, typically named after their power sources, one of the most common is electric arc welding or arc welding for short.
What is Arc Welding?
Arc welding uses a power supply to create an electrical “arc” between a metal stick, called an electrode, and a base metal material. Wherever this arc makes contact, it melts and binds metals together which become strong once cooled. While the idea sounds simple in theory, in practice it requires welders to utilize a variety of techniques with safety, skill, patience, and precision. To find out more about these techniques, let’s explore the four most used arc welding types in 2022. You’ll be surprised at just how unique each one is.
What is Shielded Metal Arc Welding?
Shielded metal arc welding (SMAW) is the most commonly utilized of all the arc welding techniques. Although it can also be referred to as manual metal arc welding (MMA or MMAW) or flux shielded arc welding, many welders who use it regularly informally refer to it as stick welding. Used in a wide range of industries including construction, industrial fabrication, underwater pipelines, and more, this technique gets its name from the stick-like electrode it utilizes to create welds.
How Does Shielded Metal Arc Welding Work?
Through either alternating or direct current (AC/DC), a welding power supply creates an electrical current which is used to form an electric arc, similar to a tesla-coil, between the electrode and the metals being joined. The electrodes used in this technique are melted into the workpiece, which is why they are considered “consumable”. When the flux coating of the electrode disintegrates, it gives off vapors that serve as a shielding gas and a layer of slag that protect the weld area from contamination in the surrounding atmosphere. Both the electrode and the workpiece melt and form a pool of molten metal known as a weld pool. Once cooled, this weld pool forms a sturdy, solid joint.
What is Flux Core Arc Welding?
Created as an alternative to shielded metal arc welding, flux core arc welding (FCAW or FCA) provides equivalent portability with better weld strength than SMAW. Also referred to as dual shield welding, FCA can be an automatic or semi-automatic process. This technique uses a continuously fed, constant voltage, consumable tubular electrode. Unlike SMAW where a shielding gas is required, FCAW electrodes often contain flux which creates its own gaseous shielding and liquid slag protection against atmospheric contaminants. Because of both its speed and portability, FCAW is used most often in construction environments.
How Does Flux Core Arc Welding Work?
The two categories of FCAW methods are divided based on whether they use external shielding or the flux core itself for protecting the weld area. Similar to SMAW, flux core arc welding fuses the base metal and electrode together through an electrical arc that strikes the area between the metallic workpieces. If a shielding gas is used, it’s typically provided by a high-pressure gas cylinder which protects the weld pool from oxidation. If instead there is no gas shielding and the welder is relying on the protection offered by the flux-cored electrode itself, the electrode provides gaseous protection along with a slag that protects the molten metal within the weld. Since the external gases can be ineffective in a windy environment, one of the main deciding factors for the welder on which method to use is whether or not the welding will take place indoors or outdoors.
What is Gas Tungsten Arc Welding?
Gas tungsten arc welding (GTAW), also known as tungsten inert gas (TIG) welding, is an arc welding technique that, unlike the previously discussed processes, uses a non-consumable electrode made from tungsten to produce welds. GTAW is widely considered to be one of the most challenging welding techniques to master. Even for expert welders, this process is time-consuming. Among the earliest adopters of GTAW was the aerospace industry, however, it is also utilized when creating the superstructure of ships in the ship fitting trade. Although GTAW produces some of the most attractive welds, it is used in circumstances where weld strength and quality are critical to the safety and success of the object and those traveling within it.
How Does Gas Tungsten Arc Welding Work?
There are two main types of GTAW processes, the more common type uses a filler metal, and the less common one does not. In both processes, the tungsten electrode forms an electrical arc between the welding torch and the work surface while inert gas, such as argon or helium, shields the welding pool from atmospheric contamination. When using filler metals, the welder must feed the filler into the weld area manually, typically by hand, where it melts into both workpieces being welded, increasing their bond. The less common process utilizing no filler metals, referred to as autogenous or fusion welds, is usually reserved for welds made on thinner materials like edges, corners, and butt joints.
What is Gas Metal Arc Welding?
Gas metal arc welding (GMAW), sometimes referred to as metal inert gas (MIG) and metal active gas (MAG) welding, is a technique that was patented in the USA for welding aluminum in the late 1940s. Since it works for thin and thick metal sections of components, it’s one of the most adaptable techniques out there. Its versatility makes it one of the most frequently utilized techniques in the automotive, metalworking, shipbuilding, and steel industries.
How Does Gas Metal Arc Welding Work?
The process can be semi-automatic or automatic. It requires constant voltage, however, similar to other arc welding techniques, it can use either alternating or direct current (AC/DC). The power supply generates an electric arc which the welder places between a consumable wire electrode and the workpiece metal. The wire is continuously fed from a wire spool by a motor drive. Wires may be solid or flux-filled, known as cored. Similar to other arc welding techniques, a shielding gas is fed through the welding instrument to prevent atmospheric contamination. The arc melts both the wire electrodes and metal workpieces together, melting and joining them once cooled. GMAW has many methods to create welds. Depending on the situation and circumstances, welders will choose between globular, short-circuiting, spray, and pulsed-spray methodologies.
Now that you know the top 4 most used welding techniques, you’re ready to learn even more. Welding jobs are some of the highest paid, fastest-growing trade jobs on the market. Welders make good money and face unique challenges every day. Whether you have no experience or you’re ready to take your welding career to the next level, Code Steel Academies is your best choice. With decades of experience in the welding industry and job placement services offered by our Direct Path Program™, your future career is just a few clicks away.