Welding is more than flying sparks here and there and the heat turning up. It is the art of transforming some of the world’s strongest materials into engineered masterpieces.
Welding is the process of permanently joining two or more metals to ensure high structural integrity and longevity, making it ideal for the manufacturing, automotive, and construction industries.
Did you know that there are different types of welding techniques, each with its unique strengths and applications? So put on that welding mask and safety goggles and dive into the flashy light show of 18 types of welding processes.
1. Stick Welding
Stick welding, also known as Shielded Metal Arc Welding (SMAW), is a manual process of joining metals. Welders use a stick, a consumable electrode coated in flux, through which electric current passes to form an arc between the stick and the metals to be joined.
The heat generated by the arc melts both the stick and the metal, forming a weld pool that turns into a strong joint after cooling. This type of welding technique is used in the construction of steel structures and in industrial fabrication.
This technique can be used to weld carbon steel, alloyed steel, stainless steel, cast iron, and some non-ferrous metals, such as nickel and copper.
2. Flux Cored Arc Welding
Flux Cored Arc Welding is an arc welding process that uses a continuously fed consumable tubular electrode filled with flux. Known for its high welding speed, and portability, the process is often used in construction projects.
It offers flexibility broadened by various operating angles, voltage levels, polarity, and faster welding speed, making it ideal for thick materials and outdoor applications. Due to the amount of smoke and fumes released during this welding process, it is advised to be used under industrial ventilation hoods.
3. Gas Metal Arc Welding
Also known as Metal Inert Gas welding, welders use a shielding gas along the wire electrode, which heats up the two metals to be joined. It is the most common industrial welding technique that requires a constant voltage and direct-current power source.
It also employs inert gases like argon or mixtures, including CO2, to protect the weld areas from atmospheric contamination.
The welding process is known for its ease of automation, versatility, and ability to produce high-quality welds on various materials, such as steel, aluminum, and stainless steel.
4. Gas Tungsten Arc Welding
Gas tungsten arc welding, also known as tungsten inert gas welding, is much more time-consuming than the stick, gas metal arc, and fluxed cored arc welding processes. It uses a fixed consumable tungsten electrode to produce the weld.
The welding process is commonly used in industries such as aerospace, automotive, and piping systems, and it is known for producing high-quality and clean welds.
5. Plasma Arc Welding
Plasma arc welding is the most precise way to produce the weld.
The process uses an ionized gas, plasma, and lower voltage to transfer a smaller arc to the metals to be joined. This makes it ideal for assembling delicate and heat-sensitive devices, such as medical devices and microchips.
The flashy light during the process can be achieved by a very high temperature in small spaces. Plasma is created by pressurizing the gas inside the wand.
Then, the plasma is ionized to make it electrically conductive, allowing the production of a high-temperature arc that can melt the metals.
6. Submerged Arc Welding
SAW, or Submerged arc welding, is a highly effective welding process that involves the formation of an electric arc between a continuously fed electrode and the metals to be joined.
The arc is generated beneath the blanket of powdered flux that provides electrical conduction between the metal and the electrode. This process also generates a protective slag that prevents oxidation and stabilizes the arc to produce a high-quality and clean weld.
This type of welding technique is widely used in heavy civil construction projects, such as shipbuilding, structural steel fabrication, and large-diameter pipelines.
7. Electron Beam Welding
Electron Beam welding is another precise welding technique that uses a high-velocity beam of electrons to melt and fuse metals together. The process involves focusing electron beams to create a small weld area, making it ideal for welding delicate and complex designs.
Due to its capability of producing deep welds with minimal distortion and high accuracy, the welding process is commonly used in industries requiring precision and strength, such as automotive, aerospace, and medical device manufacturing.
8. Atomic Hydrogen Welding
Developed in 1920 by Irving Langmuir, atomic hydrogen welding uses an arc between two tungsten electrodes in a shielding atmosphere of hydrogen.
Hydrogen serves as a shielding gas, preventing oxidation and contamination by carbon, nitrogen, or oxygen. During the process, the electric arc efficiently breaks down the Hydrogen molecules (H2) into atomic Hydrogen (H).
Later, (H) recombines, releasing a significant amount of heat that can be used to weld metals. The process can produce strong, high-purity welds in metals such as stainless steel and aluminum.
9. Laser Beam Welding
Laser welding is the process of joining metals that uses a laser as a heat source to create the weld.
Known for producing a narrow and deep weld with a highly concentrated beam of light directed onto the metal surface, the process can be used on carbon steels, stainless steel, titanium, aluminum, and high-strength low-alloy.
Due to its ability to weld thin and delicate materials without damaging them, LBW is often used in aerospace, medical, energy electronics, and industrial construction projects.
10. Projection Welding
Projection is a type of resistance welding process that joins metal components using projection to concentrate the electrical current and welding force on a small area.
The process includes creating a deep junction by the combined effect of thermal energy, developed by the current flowing, and mechanical energy, developed by the two electrodes pressed together.
During the process, high heat is generated, causing the material to soften and fuse together without heating the surrounding areas.
11. Resistance Welding
Resistance welding is the process of joining metals, in which coalescence is produced by the heat obtained from resistance of the work to flow of electric current and application of pressure.
The technique includes spot, induction, and flash welding. The most common type is spot welding, a process that produces the coalescence of metals at surfaces made to fit closely together to form a joint.
The welding process is valuable in the automotive, aircraft, and application industries because of its high-speed and repetitive welds.
12. Seam Welding
Seam welding is a process of joining work pieces of similar or dissimilar materials along a continuous seam. It is primarily used in manufacturing industries and is divided into two parts: resistance seam welding and friction seam welding.
In the resistance seam welding process, an electric current passes through the sheets of metal to be joined while they are held together by a mechanical force. It is ideal for sheet metal fabrication.
On the other hand, the friction welding process uses friction to generate heat to produce the weld rather than using electrodes. This technique is ideal for joining materials that are difficult to weld using conventional arc welding processes.
13. Thermit Welding
Thermit welding is commonly used to weld together large steel sections. It is a fusion process that uses a chemical reaction between powdered aluminum and iron oxide to generate intense heat.
During the chemical reaction, oxygen leaves the iron oxide and combines with the aluminum, producing aluminum oxide or slag and superheated thermit steel. Then, the thermit steel is run into the mold, where it preheats and mixes with the ends of the metals to be joined.
After it cooled down, a continuous joint was formed, and the mold was removed. Known for its efficiency, the welding process is ideal for railway tracks and heavy steel structures.
14. Electroslag Welding
Electroslag welding is a highly efficient process for joining thin metal plates vertically edge-to-edge. In this process, the weld takes place between the edges of the two plates, and consumable metal guides are placed between them.
A copper electrode is passed through guides, and an electric current is passed to create an arc. Then, the welding starts forming at the beginning of the seam and proceeds through the welding area.
ESW is commonly used in very thick low-carbon steel plates.
15. Gas Welding
Gas welding is the most common type of welding process. It uses heat produced by burning a gas fuel, usually acetylene with oxygen, to partially melt the metals to be joined.
It works by feeding oxygen and acetylene out of the end of a torch to produce a highly concentrated flame that can melt metal. Then, a weld pool is created, bonding the two metal pieces together to form a strong joint.
Compared to other processes, it is the cheapest and most portable welding technique. The process is suitable for metal fabrication, repair, and cutting work.
16. Stud Welding
Stud welding is an electric arc process that rapidly joins a metal stud or similar fastener to a base metal or substrate. The fastener can be threaded, unthreaded, or tapped, and the substrate can be steel, stainless steel, or aluminium.
In the process, a weld stud is joined to a metal workpiece by heating both parts with an electric arc. A fastener is attached to the workpiece, allowing almost any size of stud to be welded quickly.
Due to its ability to produce precise and high-quality welds, the process is widely used in automotive, construction, shipbuilding, and electrical manufacturing.
17. Cold Welding
It was discovered in 1940 that two clean, flat surfaces of similar metal could be strongly joined if brought into contact while in a vacuum.
Since then, cold welding has been invented, a solid-state welding process in which joining takes place without heat or fusion at the interface of the two parts to be welded. This type of welding technique is advantageous in environments where thermal expansion could be problematic.
It is commonly used in applications involving materials like copper, aluminum, and certain alloys.
18. Forge Welding
Forge welding has been used since ancient times and is a staple of traditional blacksmithing. It is a solid-state welding process of joining metals by heating them to a high temperature and then hammering them together.
Blacksmiths typically perform it, which consists of heating and forcing the metals together with external pressure to cause plastic deformation at the weld surfaces. This process is commonly used in blacksmithing, tool making, and the creation of decorative ironwork.
Wrapping Up
Understanding the various welding processes is crucial for selecting the right method for a specific application. Each process has its strengths and is suited to different types of construction projects and materials.
Whether it’s the versatility of SMAW or the precision of TIG, welding continues to play a pivotal role in transforming industrial capabilities.
