Seam welding is a popular technique used in various industries to create continuous and strong joints between two similar or dissimilar metals by using a wheel or roller that rolls along the joint, simultaneously applying pressure and electrical current. The heat generated from the electrical resistance melts the metal and forms a welded joint that is virtually invisible.
Seam welding can also be automated to produce high volumes of products with minimal labor costs, making it an ideal choice for mass production. This blog will explore seam welding and its applications in various industries.
How Does Seam Weld Works?
Seam welding joins the pieces of similar or dissimilar materials in a continuous seam. It is a widely used welding technique for both flat and corner welds.
Moreover, it offers a higher strength than any other welding technique since they are present throughout the length of a joint. A uniformly welded region created through seam welding in fusion binding is sometimes even stronger than the joined materials. Since high strength is the key property of seam weld, it is mainly employed in the process where the strength of the joint is a paramount concern.
Seam welding is a controlled technique in which a very low heat input is utilized for the under-process materials. The low input of heat minimizes the damage and helps maintain the original properties of materials. Therefore it is used in thin and delicate welding projects as well.
Types of Seam Weld
Depending upon the method of heat generation seam world is further divided into two main categories, Resistance Seam Weld and Friction Seam Weld.
Resistance Seam Weld
Resistance seam weld is a technique in which two copper electrodes work on the principle of metal resistance. When current is passed through the electrodes, an immense amount of heat is generated due to resistance between metallic electrodes.
Resistance seam welding is almost similar to continuous spot welding. The major difference between the two is the type of electrode. In resistance seam welding, roller electrodes are used, while static electrodes are used in continuous spot welding.
In resistance seam welding, the metal sheets being welded are held between the shape electrodes, and current is passed through them; the high heat production begins to melt the metal sheets held by rollers, resulting in a strong joint between them. The resistance seam welding could be either continuous or intermittent.
In intermittent roller motion, the speed of the roller is not fixed. However, in continuous resistance welding, we have a predetermined roller speed that is kept constant throughout the process.
The average speed of continuous seam welding is around 60 inches/ minute, but it varies depending on the thickness of the material, heat input, and sensitivity of the project.
Applications of Resistance Seam Weld
Seam weld has multiple applications in metal fabrication projects. Here are some of the common applications of this high-strength welding technique.
Alloy Welding
Seam weld is used for welding metal alloys like magnesium, nickel, and stainless steel workpieces.
Fuel Tanks
Since seam weld is known for its high strength and reliability, it is used in the fabrication of vehicles and aircraft fuel tanks. It is also used to make steel tanks and fuel cans since the risk of leakage is almost zero.
Refrigerators and Transformers
Metal fabrication during the manufacturing of refrigerators and transformers is a sensitive process. Seam weld is used to complete these sensitive welding projects.
Exhaust Systems
Resistance seam welding is used in the manufacturing of exhaust systems. Seam welding is a reliable and high-strength process with advantages and drawbacks.
Resistance Seam Welding Advantages
Fluid-tight and Airtight Seals
Seam weld produces airtight and fluid-tight seals, making this process highly useful for creating metallic structures that require gas, water, or liquid leakage protection.
No Overlapping
If you are concerned with the joint overlapping, choose seam welding. There are fewer chances of overlap production; if it is produced, it won’t be thicker than 10mm.
Simple Operation
Seam welding is a straightforward process, unlike plasma and arc welding. It is easy to learn, and even those not skilled can do the job. Since it’s a fully automated process, there are fewer chances of human error.
Fast Process
Seam welding is a fully automated process with the automatic transfer, loading, and unloading of materials. Since the metal does not include manual input or output, it’s faster than any other welding technique.
Controlled Process
The current is passed intermittently through the electrodes, and the heat produced is fully utilized in the welding process. The minimum heat dissipation and maximum current utilization make the process cost-effective, time-saving, and environmentally friendly.
Repeatable
The automated setup makes the process highly repeatable. Therefore, this technique is utilized in big metal fabrication projects to increase production and achieve big targets within a limited period.
Cost-Effective
Due to maximum labor input and faster processing, this is one of the most cost-effective welding techniques. The process saves much money regarding labor cost, time, and component transfer. It reduces the cost to about half of the original process.
Pollution-Free Process
The filtration material produces the major pollution associated with the welding process. Thankfully, no filtration material is used in seam weldings; therefore, no solid waste is produced. Since the process doesn’t produce any gas or fumes, its contribution to air pollution is almost zero.
Resistance Seam Welding Disadvantages
Thickness Limitations
The thickness of metal sheets is the major concern of seam welding. It becomes difficult to handle the seam welds if the thickness of metal sheets is above 3mm.
Curved Welds Limitations
Resistance seam welding uses rollers to produce high-strength uniform welds along straight lines. However, when it comes to complex and curved welds, the process cannot handle them perfectly. This is one of the major limitations of this process.
Friction Seam Weld
In friction seam, weld materials are joined together in a solid phase. Neither of the material is melted in friction seam weld. This method uses friction to generate heat instead of electrodes. This welding technique uses a rotating consumable bar with U or V shape groove. Also, have a look at how to join steel pipes without welding.
The material to be joined is pressed underneath the rotating consumable bar, and heat is generated through the friction process. No fusion of interfusion takes place during this process.
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Dave Walker
Dave Walker is a skilled welder and passionate blogger. With years of experience in welding, he has honed his craft and developed a deep understanding of the trade. In his blog, he shares his experiences, insights, and tips on welding, offering a valuable resource for fellow welders and those interested in the field. He is dedicated to promoting the importance of welding and its applications in various industries.