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Resistance welding
Professional resistance welding training is intended for both beginners and advanced resistance welding system programmers.
The main goals of our training are:
- Presentation of issues related to resistance welding technology
- Discussion of the structure and operating principles of resistance welding control systems
- Explanation of issues related to resistance welding technology for various types of materials
- Selection and optimization of welding parameters
List of training courses:
We guarantee:
- The best training conditions in a well-equipped laboratory
- Outstanding lecturers from maintenance departments and the Silesian University of Technology with extensive practical experience
- Professional training documentation allowing you to acquire knowledge in a transparent and structured way, supported by numerous examples
- Professionalism, reliability and experience the largest training center in Poland
- Individual approach to each course participant and constant supervision over the entire training course.
- Training completion certificate at the Engineering Training Center confirming acquired skills in two languages – Polish and English
- Gourmet Catering
Knowledge Zone
Resistance welding
What is the resistance welding process?
The two pieces of metal to be joined are pressed together by electrodes on the welding machine, making them in good electrical contact.
The electric current passing through them heats them until they begin to melt where they touch.
The molten metal from the two pieces is fused together; then the current is turned off and the molten metal solidifies, creating a permanent metallic bond between the two pieces.
The term "resistance welding" comes from the fact that it is the electrical property of resistance in the metal being welded that causes heat to be produced when a current is passed through it.
Types of resistance welding
There are many different types of resistance welding. Each differs depending on the type and shape of the welding electrodes used to apply pressure and conduct current.
The electrodes, typically made from copper-based alloys for their excellent conductive properties, are cooled by water flowing through cavities within the electrode and other conductive equipment of the resistance welder.
Resistance welders are designed and built for a wide range of applications in the automotive, aerospace, and industrial sectors. Automation makes the operation of these machines highly controllable and repeatable, allowing manufacturers to easily plan production.
We will now discuss several types of resistance welding:
Spot welding
This is the simplest type of resistance welding. Two or more sheets of metal are joined together, held in an overlapping position between a pair of welding electrodes: one stationary and one movable.
As current flows through the electrodes, the upper electrode simultaneously increases the downward pressure. This causes a weld to form between the two electrodes. Subsequent welds are created by repositioning the sheets.
Resistance spot welding, like all resistance welding processes, creates welds using heat generated by the resistance of the welding current flow between the substrate surfaces, as well as a pressing force applied to the workpieces for a specified time. Resistance spot welding utilizes the surface geometries of the welding electrodes themselves to focus the welding current at the desired weld location and also to apply force to the workpieces. Once sufficient resistance is generated, the materials align and join, and a functional weld pattern is created.
Resistance seam welding It is a subset of resistance spot welding, using circular electrodes to deliver welding force and current to the part. The difference is that the workpiece rolls between the circular electrodes as the welding current is applied. Depending on the specific welding current and welding time settings, the welds formed may overlap, forming a complete weld, or may simply be individual spot welds at specific time intervals.
Spot welding is ideal for a variety of applications, including:
- Automotive industry
- Aerospace industry
- Steel home furniture
- Steel containers
Benefits of spot welding
- Greater control and uniform welds
- Low price
Projection welding
This welding process also joins component parts using welding electrodes.
Electrodes are applied directly to the metal components. Opposing forces are passed through the electrodes. Typically, one of the components has one or more weld nubs to direct heat to a localized area.
Like other resistance welding processes, projection welding utilizes heat generated by resistance to the welding current and a force applied to the workpieces for a specified time. Projection welding locates welds at predetermined points using projections, embossments, or cuts, all of which concentrate heat generation at the point of contact. When the welding current creates sufficient resistance at the point of contact, the projections collapse, forming a weld nugget.
Solid projections are often used when welding fasteners. Embossings are often used when joining sheet metal. An example of projection welding using material cuts is cross-wire welding. In this case, the cut of the wires themselves localizes the heat generation and, therefore, the resistance. The wires interconnect, thus creating a weld nugget.
This is a very efficient process and is not as dependent on the electrode as spot welding. The welds and projection processes are designed and developed to suit a variety of applications.
Advantages of projection welding
- Flexibility
- Better-looking joints
- Welding spots can be positioned closer
Flash welding
Like other resistance welding processes, flash welding utilizes heat generated by resistance to the welding current and a force applied to the workpieces for a specified time. Flash welding is a resistance welding process that generates resistance by flashing. This action is achieved by using very high current densities at very small contact points between the workpieces. At a specific point after the sheet metal process begins, a force is applied to the workpieces, and they are moved together at a controlled speed. The violent agitation created by this force removes oxides and contaminants from the weld.
Advantages of resistance welding
Regardless of the type of resistance welding chosen, they all share similar characteristics. Here are the most important ones:
- High welding speed
- It is often automated
- You can weld similar and dissimilar metals together
- High production efficiency
- Environmentally friendly process
- No need for filler metal, flux or shielding gases
