Over the years, different types of welding processes have become available due to the advancement of technology. The conventional method, known as arc and gas welding, has been used to create modern ones that work on different principles. Welding is one of the most important skills in today’s world, as strong metal materials are put into shape.
Welding is hazardous and can easily cause burns and vision damage. It could cause the intake of poisonous gas, electric shock, and exposure to ultraviolet radiation. Welding operations can be performed underwater, in outer space, and in the open air. Different energy sources are used for the process.
Industries require highly skilled welders, which is why the StudentLesson team provides in-depth knowledge of the various welding processes.
Types of Welding Processes
The following are the types of welding processes you should know:
- Gas-tungsten arc welding (GTAW/TIG)
- Gas-metal arc welding (MIG/GMAW)
- Shielded metal arc welding (SMAW)
- Plasma arc welding (PAW)
- Stick welding
- Flux-cored arc welding (FCAW)
- Gas welding
- Submerged arc welding (SAW)
- Electron-beam welding (EBW)
- Laser beam welding (LBW)
- Atomic hydrogen welding (AHW)
- Resistance welding
- Electroslag welding
- Thermit welding
- Forge welding
- Friction welding
Gas-tungsten arc welding (GTAW/TIG)
Gas-tungsten arc welding, also known as tungsten inert gas welding, is one of the most common methods adopted. It is often used for welding thick sections of stainless steel or non-ferrous metals. This is an arc welding process that uses a fixed consumable tungsten electrode to get the weld. The process is much more time-consuming than other arc welding processes. Read the full article on gas-tungsten arc welding here.
Gas-metal arc welding (MIG/GMAW)
Gas-metal arc welding is also known as metal-inert gas. It is a semi-automatic, quick process where filler wire is fed through the gun, and shielding gas is applied around to protect from environmental impurities. Filler wires are used during the process. The tip of the wire acts as an electrode to create the arc with base metal, which melts as filler material to create the weld.
MIG welding processes are mostly used in automotive repair, construction, plumbing, robotics, and the maritime industry. These welding types are sensitive to external factors such as rain, wind, and dust, making them unsuitable for outdoor use. Dross and porosity are some limitations of MIG welding, as they make the structure weak. Read the full article on Gas-metal arc welding here.
Shielded metal arc welding (SMAW)
Shielded metal arc welding produces strong welds with deep penetration. The process requires minimal preparation, and it is quick and efficient. It protects the welder from UV light and infrared radiation because of the flux layer. These types of welding involve the covering of metal pieces, welding wire, arcs, and welding joints with a blanket of flux. This makes the process safe as there are no emissions of welding fumes, strong arc lights, or flying slags.
The welder follows a manual process of stick welding. The stick uses an electric current to form an arc between the stick and the metals to be joined. The welder must be able to weld to a level at which their work can pass a destructive type of bend test. You can read about welding inspections here.
Shielded metal arc welding is used to weld carbon steel, alloyed steel, stainless steel, cast iron, and ductile iron. It can also be used for some non-ferrous metal applications, like nickel and copper. It is rarely used on aluminum. It is a faster process for high-production industries.
Plasma arc welding (PAW)
Plasma arc welding is similar to GTAW; it uses a smaller arc and lower voltages. This increases the precision of the weld. The precision and voltage allow the process to be used on delicate and heat-sensitive devices, such as microchips and medical devices.
The torch can also achieve very high temperatures within a short time. Gas is pressurized inside the wand, which helps in creating the plasma. The plasma is then ionized, making it electrically conductive. This allows the arc to be created, producing incredibly high temperatures that can melt the base metals.
These types of welding processes can be used in a very low-current mode, making it a good option for delicate computer parts. Electronic chips can be sensitive to environmental factors like excess heat, which is why low current is particularly effective in these use cases. Read the full article on PAW here
Stick welding is also known as arc welding. It is one of the conventional methods of welding, as it uses a replaceable stick electrode. The arc is generated when the end of the stick contacts the base metals. The heat of the arc melts the electrode’s filler metal to make the weld.
It coats the stick electrode with a flux that creates a shielding cloud to protect the weld zone from oxidation. The flux on cooling changes into slag, which needs to chip off.
The advantage of these types of welding is that it is possible to perform the process outdoors and in different weather conditions like wind and rain. It is possible to weld on rusted, painted, and dirty metals, so it is useful in equipment repair. Read the full article on arc welding here.
Flux-cored arc welding (FCAW)
These types of welding processes serve as an alternative to shield welding. It is also a semi-automatic arc weld that is often used in construction projects due to its high welding speed and portability. This method has many variables, making it applicable to a variety of welding projects. These variables often depend on the model of the welder being used and what type of wire was chosen.
Flux-cored arc welding is best used in outdoor settings or under industrial ventilation hoods due to the amount of smoke and fumes produced during the welding. The process offers a lot of flexibility, which includes the polarity used, speed of the wire feed, and voltage levels. Due to the potential for faster welding speeds, the newly joined metal cools quickly. Read the full article on flux-cored arc welding here.
Gas welding is a conventional type of welding process; it has been largely superseded by tig welding. The process involves the use of oxygen and acetylene in cylinders. They are mostly used to weld bits of car exhaust together.
Gas welding is one of the hottest methods of welding, at 3500 degrees Celsius. It generates heat when a mixture of fuel gases and oxygen passes through a torch. The process involves three types of flames: neutral flame, carburizing flame, and oxidizing flame. Read the full article on gas welding here.
Submerged arc welding (SAW)
These types of arc welding processes involve the formation of an arc between the electrode and the workpiece. A blanket of granular fusible material shields the arc on the workpiece. Submerged arc welding involves the covering of metal pieces, welding wire, arc, and welding joint by a blanket of flux.
This makes the process safe as there are no emissions of welding fumes, strong arc lights, or flying slags. The flux barrier protects the welder. The process is faster, which is why it is used in high-production industries.
In addition, SAW produces strong welds with deep penetration, with minimal preparation, quickly and efficiently. It protects the welder from UV light and infrared radiation due to the flux layer. Read the full article on SAW here.
Electron-beam welding (EBW)
Electron-beam welding works with a beam of high-velocity electrons to join materials. It is performed in a vacuum (with the use of a vacuum chamber) to prevent the beam from dissipating. The kinetic energy of the electrons transforms into heat upon impact with the material, causing it to melt together.
Among many of its applications, EBW can be used to join thick sections. This means it can be applied across several industries, from aerospace to nuclear power and automotive to rail.
It is also used in aerospace components, bimetal saw blades, and transmission assemblies. It is a perfect choice to seal electrical components. These techniques are good for dissimilar metals of various melting points and thermal conductivities. It is also good for thin and thick metals.
Laser beam welding
These types of welding processes are used on metals or thermoplastics. It works by using a laser as a heat source to create the welds. Laser beam welding can be used on carbon steels, stainless steel, and high-strength low-alloy (HSLA) steels like DOCOL®, titanium, and aluminum.
The process is easily automated with robotics, which is why it is often used in manufacturing, such as in the automotive industry, aerospace, medical, energy, and electronics industries.
The applications of laser welding are most prominent in the automotive industry, where lasers boost productivity at a low cost when welding automotive parts, such as roofs, doors, or filler assemblies.
Atomic hydrogen welding (AHW)
These are arc types of welding processes that use an arc between two tungsten electrodes in a shielding atmosphere of hydrogen. The process was invented by Irving Langmuir in the course of his studies of atomic hydrogen. The welding process is known to be replaced by MIG welding.
The process can fuse without changing the metal when welding them. The two metal tungsten electrodes are placed in a hydrogen atmosphere. The hydrogen molecules in explosive heat can produce heat up to 3000 degrees Celsius. Welders are highly expected to follow the safety precautions like wearing welder gloves, suits, goggles, and helmets. You can read about arc welding safety precautions here.
Resistance types of welding processes are known to be seam, spot, projection, flash, high, and low-frequency welding. These processes are used for a very high rate of production. Spot and seam welding require heat for joining which is generated at the interface by electrical resistance.
Spot welds are suitable and mostly carried out on sheet metal that requires overlap. This welding process is achieved in a short time using a voltage, high-current power as the heating service is applied to the joint through two electrodes with force. The strength of the joint is determined by the size and number of welds.
Electroslag welding bonds heavy metal pieces used in machines and industrial equipment. The process takes place in a vertical position that allows for a view of the weld as it takes shape. The method gets its name from the copper water holders contained inside the tool used for electroslag welding. This welding process is very fast.
Thermit welding consists of a mixture of aluminum powder and iron oxide. It is ignited to result in an exothermic reaction that is non-violent. The excessive heat melts the metal and pours at the joint surfaces. The liquid metal solidifies on cooling to create a solid welding joint.
It is a simple and fast method to weld similar and dissimilar metals. This welding process does not need any power supply, it only requires heating the thermite at 1300 degrees Celsius.
These types of welding processes are fashion techniques that have been applicable since the earliest uses of iron. The process is done by pressing or hammering hot pieces of metal. At first, it turns small pieces of iron into larger, more useful ones by joining them. Forge welding temperature before being hammered or pressed together. This welding process is used by blacksmiths mostly to make items like swords and chains.
Friction welding is another type of welding that is performed by bringing the workpiece together under load with one part revolving quickly. The heat is created at the interface until it becomes plastic. The rotation is then stopped, and the load is increased to produce the joint. As a result, strong joints are made with the help of plastic deformation. Read the full article on friction welding here
That is all for this article, where the different types of welding processes are discussed. I hope it was helpful, if so, kindly share it with others. See you around!