There are many ways to join metals, and welding is a necessary technique for connecting many metal parts. If you’re new to the welding industry, you might not realize how many different welding processes exist to connect metals. This article will explain the main 8 welding processes, giving you a deeper understanding of the welding industry.
Arc welding is a process that uses an electric arc as a heat source to melt and fuse the surfaces of workpieces together. It is the most common welding technique and includes methods such as manual arc welding and gas shielded welding. The choice of arc welding method depends on the material and welding requirements. For welding structural steel, manual arc welding is used, while gas shielded welding is better for materials like stainless steel and aluminum alloys. It is important to protect the welding area to avoid oxidation and sparks and to carefully control the machine’s current and voltage settings to achieve the best results.
In MIG/MAG welding, the welding torch delivers the welding wire connected to the power source. An electric arc is created between the welding wire and the workpiece, melting both the workpiece material and the welding wire to form a weld seam, thereby joining the workpieces together. During welding, the welding torch continuously feeds the wire and supplies shielding gas to protect the weld seam.
MIG welding is widely used and suitable for welding large, immovable workpieces. It is commonly applied in heavy industries such as shipbuilding, pipeline construction, and steel structures, and is also used for the repair and maintenance of such projects.
TIG welding, also known as Tungsten Inert Gas welding, is a method that uses an external gas as a protective medium. TIG welding employs a non-consumable tungsten electrode to join metal materials. The process generates a high-temperature arc that melts and fuses the metal workpieces together.
TIG welding is known for its high welding quality, precision, and clean, aesthetically pleasing welds. It is particularly suitable for precision components and thin materials like stainless steel and aluminum. This method is mainly used in industries such as automotive, aerospace, and precision manufacturing.
Resistance welding involves placing the workpieces between two electrodes. Heat is generated by the current, causing the workpieces to melt and fuse together under pressure. Resistance welding is divided into four main types: spot welding, projection welding, butt welding, and seam welding. The appropriate welding process is chosen based on the welding needs of the workpieces.
Compared to other welding methods, resistance welding has several advantages: it does not require welding wire, it is fast, and it is suitable for welding small metal parts. It is also easy to automate, making it widely used in industries such as automotive parts, electronics, and home appliance manufacturing. For example, if you need to weld an automotive nut, you can choose resistance welding.
Laser welding is a method that uses a laser beam as the energy source to precisely heat and join metals or plastics. Compared to traditional arc welding, laser welding is faster and more efficient. It is a key technique in laser material processing. Laser welding does not require electrodes and does not need to contact the workpiece material. When welding thin materials or fine wires, it does not cause back melting like arc welding.
Plasma welding uses a high-energy arc to generate plasma, heating the workpiece surface to its melting point. Welding material is added, melting and fusing with the workpiece. This method can weld various materials, including metals, plastics, and ceramics. It is widely used in aerospace, automotive manufacturing, and electronics.
Ultrasonic welding uses high-frequency vibration waves applied to the surfaces of two workpieces under pressure, causing them to rub together and form a solid-state weld. This method can be used for both metals and plastics and can also connect dissimilar materials. In metal welding, high temperatures disperse oxides on the surface and create localized motion in the material, forming the weld without melting the material. Ultrasonic welding produces very precise and clean joints and is an easily automated welding method.
Friction welding generates heat through the high-speed friction between two workpieces, softening and fusing their surfaces. The melted surface layer is then expelled, and the joint is formed as it cools. This is a solid-state welding and bonding process. Friction welding does not require an external heat source, which helps prevent defects like deformation and cracks due to excessive temperature. It is also energy-efficient and produces strong welds. You can use it to weld metal to metal or metal to non-metal, and it is widely used in industrial production, such as for aircraft wheels and railway vehicle axles.
When choosing a welding process, consider factors like the materials, thickness, size of the workpieces, and the welding requirements. It’s important to conduct multiple tests to determine the most suitable welding method.
1、Which welding technology is more suitable for the automotive industry?
Resistance welding is more suitable for welding automotive components. Its advantages lie in its firm and aesthetic welds, fast welding speed, and easy implementation of welding automation.
2、What materials can be welded?
Generally, various metal materials such as stainless steel, copper, aluminum, galvanized steel, etc., can be welded.
3、What types of filler materials are there for welding rods?
The type of welding rod varies depending on the welding process. For resistance welding, this process does not require welding rods.
4、Where can I learn more welding skills?
You can learn welding techniques at specialized vocational schools or by studying in factories.