1.3 Tack Welding
1.4 Striking and Maintaining the Arc
1.6 Shielding
2.1 Arc Welding
2.2 Stick Welding
2.4 TIG Welding
2.7 Laser Welding
2.8 Friction Welding
Manufacturers prefer welding because this process makes the material joints strong, permanent and durable. Normally, manufacturers do welding on metals and thermoplastics. Through welding you can create bonds between two or more materials, but you can’t create bonds between dissimilar materials with this method.
For creating weld joints, you must use high temperature or pressure. Sometimes you may require both and filler material is not also mandatory in the welding process. In this method, you will melt the materials at high heat and join them at an atomic level. As you make the metal joints by melting the original metals, it will be as strong as the original metal.
You need to first prepare your materials before starting the welding process. Welding can be done on good quality and clean materials, otherwise, the quality of the weld joint won’t be good. So if there are any contaminants on the surface of the material like rust, oil, paint or any other dust, clean them by mechanical cleaning, wire brush or grind.
For conducting welding successfully, selecting the right equipment is necessary. Before selecting equipment, you must decide the materials and welding technique you will use. Because your metal thickness, joint design and the process will influence the applications you have to use during the welding. After selecting the equipment you need to set them to commence the process. You will set up the welding machine for parameters like current, voltage, and wire feed speed so that it can get the required heat and mode of metal transfer.
It’s necessary to prepare a track weld, before beginning the original welding process. Track welds will help you to keep the materials aligned during the whole process. Without track welding, it’s difficult to hold metal pieces in place. As a result, it can affect the weld joints quality. The track welds are small in size, and the maximum their length can be 12 to 25mm. But without these, completing the welding process is difficult.
Striking and maintaining the arc is crucial to making proper metal joints as the welding process starts with it. With electrodes or wire, you will produce the required heat to melt the materials. To provide heat, you will strike the base material with electrocide or wire. You must withdraw the wire immediately after touching the surface, otherwise it can overheat the metal. To maintain the arc, you must maintain the arc length. The arc length must be between 2-6mm controlling the angle and speed of the welding gun.
In the next step, you need to control the molten pool that is created from the welding. Controlling it is important as through it joining of materials takes place. To get the desired result, you need to manipulate a lot of things like heat input, travel speed and also the welding gun or torch. You need to control these factors as they will determine the quality and integrity of your metal joints.
To create high-quality weld joints, you must protect the welding area from atmospheric interference. And for that, you have to use a shielding medium. Different shielding mediums are used for different welding processes. In welding processes like GMAW, GTAW and SMAW you will flow a shielding gas like argon, or helium over the welding area.
In the next step, you need to add filler metal by continuously moving electrodes or wire while maintaining all the other things like a molten pool, arc and shielding. By doing this non-stop you will create a weld bread and fusion between the materials. Especially for creating thick sections in weld joints, multi-pass welding is required. With that, you also need to control the inter-pass temperature. The inter-pass temperature must be below 250°C to save it from any kind of heat damage.
After creating the welding pass, you must clean that area by using a brush, grind or other weld-cleaning equipment to remove impurities or any dirt from the surface. Cleaning these impurities will increase the strength and quality of the weld joints.
Inspection
After producing the weld joints, keep them for rest and cool. Then thoroughly check all the weld joints to find any imperfections or defects on them. Some defects you can detect from visual inspection but for inspecting the quality and the integrity of the metal joints you must use some tools like ultrasonic testing or X-ray.
Finishing
After inspecting the weld joints, you will provide post-weld treatment if any of them require that. After that start the finishing process to improve the look and performance of the weld joints. Remove extra metal from the weld joint and smooth the edges to make it more aesthetic.
In arc welding, you will join two metals by using an electrical arc. Through the electrical arc, you will create intense heat around 6500°F (3600°C) to melt the metal parts. In this welding process, we use shielding gas like argon or carbon dioxide to protect the molten metal from the environmental effects. This welding process manufacturers normally use in construction, repair and fabrication works.
Stick welding or shielded metal arc welding (SMAW) is a manual arc welding process. In this process, the welder uses a flux-coated electrode. For melting the material you will strike an arc between the electrode and the metal pieces you want to join. When you strike the flux coating starts to melt. A gas is also realized in this process which helps to protect the molten metal. As the electrode melts and adds the final weld joint, it makes the material joint more strong.
Gas metal arc welding (GMAW) is known as an automatic or semi-automatic welding process. Many people know this process as MIG welding. Welders use a welding gun to feed the wire electrode. Through this continuous process, welders melt the wire and create a weld puddle. And after cooling this weld puddle turns into a strong weld joint. This welding process is popular for its simple and effective procedure and for creating high-quality joints.
In the TIG welding process, a tungsten electrode is used for the welding arc. But you won’t melt the tungsten electrode and it’s not going to add with the metal joints. But it will act as the conductor for providing electricity. You will manually provide a filler metal rod inside the arc to melt. The filler rod will melt with the original metals and make the weld joint strong. This process is great at producing durable metal joints but for handling this needs skilful operators.
In the plasma arc welding process, a hot plasma arc is used to produce the weld joints. This arc is extremely powerful and can melt most of the materials. Through this welding process, you can make deep and narrow welds, without affecting the surrounding areas. Plasma arc welding is very popular in industries like manufacturing and aerospace.
In the electron beam welding process, a beam of high-speed electrons is used for melting and joining the metal parts. Through this process, you can create a strong bond within metal parts without any filler metal. This welding process is well known for creating precision and high-quality weld joints with minimal damage. But for conducting this welding, you will need specialized equipment.
In the laser welding process, you will use a high-energy laser beam to create heat for melting and bonding the metal parts. Through the laser beam, you will give high heat and create a deep weld joint. You also don’t need any filler material in this welding too. Through laser welding, you can weld different types of materials. But for conducting this, you will require specialized laser equipment. This process is widely used in industries like electronics, jewelry, and automotive.
In the friction welding process, you will two metal parts together by using frictional heat. To create the weld joints, you have to rub the two metal parts at high speed until they produce heat and join them together. When the metal parts start to melt, you will join them by creating pressure. Through this process, you can create strong weld joints with low heat.
Welding is a well-known and reliable technique for creating high-strength and long-lasting metal joints across different industries. There are many types of welding processes available. Each welding has its advantages and characteristics. Many welding processes you can do manually with little equipment. And for conducting some you will need specialized equipment and skilled operators. For selecting the right one you must understand their application and how they work, Then choose the most suitable one according to your needs.
