Spot welding is still used today even though it was one of the first methods of welding employed. The advantages and industrial uses of this welding technique are numerous. But you may not know What is a Spot Welding? and How does it work?
In this article, weldfaq will provide you with not only that but also much other information such as applications, advantages, and disadvantages of spot welding. Start with the concept that will make you understand better!
What is a Spot Welding?
Spot welding is the method of joining two or more metal sheets together by applying force and heat from an electric current to the joint. Resistance welding, also referred to as spot welding. It is the most straightforward and widely used technique for creating superimposed joints in thin sheets up to a thickness of 12.7 mm.
A typical spot welder is made up of electrodes attached to the ends of the secondary coil to conduct the current to the job site and a transformer to create high current at low voltage. Additionally, there is a setup to deliver the required mechanical pressure and bring the electrodes into contact with the work.
How does Spot Welding work?
All workpieces and sheet metal are lined up before welding begins. Because the plates cannot be separated once they have been welded together, this operation is crucial. Selecting the appropriate electrode to weld your workpiece is a step in the electrode transfer process. Due to their improved resistance to oxidation and heat retention, the majority of welders choose to utilize pure heat-resistant copper electrodes.
The weld materials are pushed and overlaid between two water-cooled electrodes during the spot welding process, and a strong current is then passed through the assembly. The junction is cooled under pressure while the metals in the pressure zone are heated to their melting points.
The needed welding current for the spot welding method is approximately 5000 A, and the electrode voltage is typically less than 3 V. The open circuit voltage is also lower than 12 V. On the transformer’s primary winding, connections are provided for controlling the secondary voltage and current.
The three primary phases of spot welding are as follows. The metal workpiece is exposed to copper alloy electrodes in the first step. Despite the electrodes, the current then quits. Using specific channels that cross through the centers of the copper alloy electrodes, the metal workpieces are cooled after the current has been turned off.
Uses of Spot Welding
Manufacturing of electronics:
Gas sensors, solar panels, switches, high voltage cables, and circuit boards are just a few examples of the products that are frequently produced with spot welding. This process is renowned for having great resilience, which makes it perfect for producing delicate and intricate electronic devices.
The automobile industry is widely renowned for the accessibility and low cost of spot welding. Additionally quick, this technique offers a straightforward and efficient solution to weld metal sheets for the production of automobiles. Using this strategy, manufacturers can maximize profits by making the most of the limited time and producing more automobiles every shift.
When making batteries, resistors are used to identify solder wires with nickel-metal hydride, lithium-ion batteries, or nickel-cadmium cells. Spot welding the battery connections using thin nickel bands. Due to its ability to reduce battery heating, this approach is frequently preferred over traditional soldering.
In dentistry labs, spot welding is used for a variety of procedures. By using electric welding, this technique is utilized to heat or repair orthodontic materials. Spot welders can be used by orthodontists to anneal wires for fixing implants.
Pros and Cons of Spot Welding
Pros of Spot Welding
- Due to the low cost of the procedure, spot welding is an excellent approach to cut costs without compromising the quality of your items.
- To employ electrical energy for the welding process, spot welding offers a far more effective solution.
- It is possible to link together many panels at once and weld panels as thin as 1/4 inch into position.
- Numerous metals are compatible with this welding technique. Welds between two metals that aren’t compatible can easily be found.
- The efficiency and homogeneity of spot welding are very compatible.
- The metal workpiece is typically made harder because heat is used to melt and melt the surfaces of the metal workpiece.
- The best method for welding light metals—typically aluminum—together without burning is spot welding.
- The typical welding time for spot welding is only 0.01 to 0.63 seconds, making it a quick process. Depending on the metal’s thickness, the force applied by the electrodes, and the electrodes’ own diameter.
Cons of Spot Welding
- Around the spot where the metal was spot-welded, warping and fatigue loss may take place. The joint’s shape is typically extremely poor, and there may be fissures.
- Spot welding uses a very heavy welding gun that is extremely difficult to use. Because of this, spot welding can be extremely hazardous for seasoned welders.
- The force, temperature, and cleanliness of the electrode and metal are all factors that affect how strong a spot weld is.
- By employing a portable spot welder, it is possible to circumvent the challenge of joining electrodes to unusually shaped bits of metal.
Frequently Asked Questions & Answers (Weld FAQ)
Is spot welding dangerous?
Spot welding carries some risk. Spot welding requires the use of very powerful welding guns since they are so heavy. This technique is extremely risky because of these features, especially for seasoned welders.
When welding, extremely high temperatures can result in serious burns if they come into touch with the welder’s skin. Additionally, welding exposes workers to hazardous fumes and sparks constantly, putting their health at risk. Collisions and self-injury, particularly to the hands and fingers, are additional concerns for welders.
Can spot welding be used to weld thick materials?
Spot welding is typically used to combine materials that are thin and have a thickness of no more than 3 mm. When joining pieces of various sizes, the thickness ratio cannot be higher than 3:1. The amount and dimensions of each material will affect how strong the final weld is. A spot weld diameter of 3 mm to 12.5 mm should be present on your finished product.
What materials are suitable for spot welding?
Steel is generally simple to spot weld due to its lower thermal conductivity and higher resistance, with low carbon steel being the ideal choice. Compared to uncoated steel, galvanized steel requires a slightly greater welding current. Copper electrodes also quickly deteriorate the surface of zinc alloys, which results in poorer-quality welds. Other materials that are frequently spot-welded include titanium, nickel alloys, and stainless steel.
Spot welding is a simple process to use. Robots that have been programmed or trained personnel both have success with this technique. This welding technique is being employed more frequently as a result, which helps the production process run smoothly.
Above is information about What is a Spot Welding? and what about spot welding. Spot welding is relatively simple because the process does not use shielding gas and filler material at all.
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