Plasma welding: installation, technology, principle of operation, application
Traditional methods of welding in many areas gradually fade into the background, giving way to more technological means of solving such problems. Many construction companies and industries that require high accuracy of assembly operations, use methods of plasma welding. This is one of the modern technologies that provide many advantages. In particular, plasma welding is distinguished by its economy of resources and high quality results. At the same time, the use of this method involves taking into account many technical nuances.
The principle of the method
In the process of implementation of the welding operation, the metal sheet melts with plasma. The generation of the stream itself is provided by a compressed high-speed arc fed by a plasma torch. The working temperature of the active stream can reach 30,000 degrees.An important feature of the technology is the admission of gas to the active arc region, which stimulates the ionization process. The produced particles of the gaseous medium become the cutting enzyme acting on the metal. At the same time, different intensity of the fluxes that plasma welding is capable of generating is noted. The principle of operation of this technique is a bit like argon welding. The main difference is the high temperature of the plasma, which allows the use of the method in a wider range of installation work. The quality of the process will depend on many factors, including the characteristics of the equipment used.
Plasma Flow Welding Technology
The organization of work activities involves the use of equipment that will ensure the generation of electricity and the release of compressed air. If a compressor is used, then only electricity is required from additional resources. The complex of equipment providing the generation of a compressed arc for cutting can also be a special burner. The arc between the electrode and the product is produced through a nozzle having a small size.This is another important difference in plasma processing - the cutting welding beam deforms the metal along a thin line, allowing you to save working material and increase the accuracy of the final weld. Another plasmatron nozzle, which is designed to protect the combustion zone from the negative effects of air, is activated during the course of the work. In other words, plasma cutting and welding is performed under vacuum conditions, which eliminates accidental unwanted deformations of the workpieces. Depending on the conditions of the work, sometimes cooling of the active area with water flows is also required. This measure also serves to stabilize the parameters of plasma exposure to the working surface.
Varieties of technology
Specialists divide plasma cutting operations into two groups depending on the characteristics of the current. For example, microplasma cutting is performed at a current of up to 25 A, allowing you to cope with thin sheets of soft metal. Average currents of the order of 100 A allow for larger volumes, but are not suitable for high-precision missions. The most efficient welding requires the use of a 150 A current source — this group of operations is used in industry.Microplasma plasma welding technology is beneficial in that it eliminates the formation of burn-throughs on the metal surface. In turn, a large current provides for the complete melting of material up to 1 cm thick. If it is required to perform a combined operation in the form of cutting and welding, then equipment using current sources from 100 A is more often used. melting They differ in that in the first case the electrode is held between the workpiece and the plasma, and in the second the arc acts directly on the target area.
Plasma Welding Equipment
Apparatus for plasma welding allows you to work with different types of metals from aluminum to titanium and galvanized alloys. The most common technical tool of this type is the mentioned plasma torches and torches, which are capable of melting material through a thickness of 8 to 12 mm. There are also modifications that implement the specific cutting of thin-sheet 0.5-millimeter metal without the formation of deformation and leads around the edges.Plasma welding inverter units operating under DC conditions are considered standard. Moreover, the torches are usually supplied as standard, allowing in the future to realize both plasma and argon-arc welding. More modern versions are equipped with electronic control panels and elements of the robotic performance of individual functions.
Plasma Welding Machine Manufacturers
High-tech devices are developed by FoxWeld, Hyosung and Fimer, offering equipment for 50-100 thousand rubles. depending on the modification. These are small portable devices that allow manual operations. More respectable installations are produced by manufacturers Migatronic and Tetrix. In this case, we can talk about multifunctional and powerful tools intended for specialized work in industrial environments. These models cost about 300-500 thousand rubles. Domestic products are also presented with decent options. In particular, the plasma welding machine "Gorynych" is a universal generator of low-temperature plasma flow, which is optimally suitable for non-combustible materials.Interesting solutions are also offered by Plazar, in whose family you can find high-quality mobile devices for welding.
Infrequently, plasma torches are encountered, which are limited only to cutting and welding functions, although these operations are undoubtedly key. The third most important adjacent option is soldering. Solder is performed with soft and solid metal alloys under high temperature exposure. Also, many modifications allow the operator to produce bluing, thermal oxidation, powder spraying and hardening. Multi-component plasma welding is not always characterized by high quality, but it justifies itself in the conditions of continuous mass production. The specialized operations that can be performed by some models of plasma torches are the formation of chemical compounds, the ability to process glass and glaze.
According to the characteristics of the workflow, this method is considered one of the most profitable. We should start with the fact that the arc itself is small in size.In practice, cutting this means minimizing the deforming phenomena, which gives a clean and even seam. In addition, the user can change the parameters of the arc during the welding operation, without fear that the correction will affect the quality of the result. Smooth change in cutting also improves work efficiency. If manual plasma welding is planned, then the operator can count on the product of voluminous work in a long-term mode without loss of thermal impact power. High-temperature processing of metals with complex structure expands mounting possibilities. Powerful installations that implement this type of welding are suitable for connecting and servicing elements of critical structures and communication networks.
Disadvantages of the method
The main disadvantages of technology are related to the complexity of the technical organization of the process. Although manufacturers are striving to develop compact and at the same time functional installations that have everything they need in basic equipment, the operator must track several processes at the same time when performing work. Thus, in addition to direct welding, it is necessary to control the stability of the water supply and the supply of gas generating the active medium.In addition, plasma welding has a high loss of energy that is dissipated into the environment. But this is a minor drawback, since the equipment initially uses the medium-sized resources compared to other modern technologies of cutting and melting metal.
Spheres of application
The possibility of creating an even and hermetic seam determined the wide spread of plasma torches in the areas of food, energy and chemical production. Enterprises of this profile are engaged in the manufacture of fire extinguishers, tanks, boilers, gas cylinders, tanks and pipes, etc. In the construction sector, the use of plasma welding is justified in the manufacture of sheet metal and finished metal structures. High-precision welding tasks performed using this technique have found their place in the manufacture of medical equipment, electrical engineering and instrument-making.
In choosing the right method of joining metal blanks, specialists take into account many factors. Plasma as a working environment, of course, is not in all respects the optimal solution, but in some respects this option is the best.For example, plasma welding is suitable in cases where high precision weld formation is required. The melt during such processing is obtained both externally aesthetic, and rather dense in structure, which determines the tightness of the joint. Plasma is also suitable in situations where a low-cost but relatively fast and versatile welding method is needed.