The welding process of stud welds is as follows: First, connect the power supply of the welding machine's gun and place the cylindrical stud on the gun. Start the gun, and the current will melt the stud while generating an arc. After a period of time, the cylindrical stud will press the end of the base material at a certain speed and melt. Finally, cut off the power supply to complete the stud welding and fix it to the base material.
In addition, stud welding is a welding method that heats the stud and the base material locally through an electric current. It also applies pressure to ensure a firm bond between the stud and the base material. This welding method can be divided into two types: arc stud welding and energy storage stud welding.
In arc stud welding, the stud end is placed in a ceramic protective cover and connected to the base material for power supply. This excites the arc between the stud and the base material, and the heat of the arc melts both. After a certain period of arc burning, the stud is pressed into the local melted area of the base material to complete the welding. The ceramic protective cover's function is to concentrate the arc heat, isolate the external air, protect the arc and the molten metal from nitrogen and oxygen damage, and prevent the splashing of molten metal.
On the other hand, energy storage stud welding uses alternating current to charge a large-capacity capacitor and then discharge it instantaneously to the stud and the base material to achieve melting. Due to the limitation of the capacitor discharge energy, this method is usually suitable for stud welding with a small diameter (less than or equal to 12mm).
The process parameters of stud welding include current, power-on time, stud extension length, and lifting height. The selection of these parameters should be based on the diameter of the stud, the surface condition of the welded steel, and the coating material. Generally, as the stud diameter increases or the coating on the base material exists, the required current, time, etc. will also increase.
Stud welds, as a high-strength and stiffness fastener, play a crucial role in arc stud welding. This type of stud is usually referred to as a cylindrical head stud, and its material can be carbon steel or stainless steel. The surface of carbon steel stud needs to be treated with copper plating, while the stainless steel one remains its original color. Moreover, stud welds have two types of threads: external threads and internal threads. Among them, the stud with internal threads is often called a spot welding nut column or internal thread stud column.
When performing stud welding, first place the end of the welding stud in contact with the connected surface and apply power to initiate the arc. After the contact surface melts, apply a certain pressure to complete the welding. Then, pass the other end (i.e., the threaded end) of the stud through the through-hole of the connected component and attach a washer and tighten a nut to ensure that the two connected components can be smoothly connected as a whole.
The main equipment for stud welding includes stud welding power supply and welding gun. Its basic principle is to ignite an arc between the stud to be welded and the workpiece. When both are heated to the appropriate temperature, the stud is sent into the welding pool on the workpiece by external force, thus forming a welding joint. Depending on the type of welding power supply used in the welding process, traditional arc stud welding can be divided into ordinary arc stud welding and capacitor energy storage arc stud welding.
Stud welds have wide applications in many engineering fields, including high-rise steel frame structures, industrial plant buildings, roads, railways, bridges, towers, automotive manufacturing, energy facilities, transportation facility buildings, airports, stations, power stations, pipe supports, lifting machinery, and other various steel structure projects.
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