Termite welding: technology. The practice of thermite welding in everyday life and in the electrical industry

The product of welding operations, regardless of the technology used, is associated with the need for a rather troublesome organization of the work process. The master must prepare equipment, supplies, and also take care of safety. In this case, it is necessary to take into account the cost of the event, since the financial provision of such operations in the regular regime does not always justify the quality of the result obtained. In this regard, one of the most profitable is termite welding, characterized by ease of implementation, the availability of materials and in some cases allows achieving high strength joints.

Technology features

The process of welding with termites is characterized by the use of special powder mixtures, which during the combustion produce a large amount of heat. As a rule, these are metallic mixtures, which are called termites. The traditional combination involves the use of two components - the ignition mass and the composition from which heat is released. As an oxide, scale from iron appears, and the main activator is a termite containing magnesium and aluminum. In addition, the technology of thermite welding allows the use of chromium, tungsten and nickel oxides . Due to these powders, the thermal effect is enhanced. So, if a mixture of aluminum and magnesium provides heat of about 2500 ° C, then the chromium compounds raise the temperature to 3500 ° C. There are also mixtures for fuse. The most common composition for this task is a combination of magnesium, sodium and barium peroxide. The peculiarities of a burning termite include the maintenance of active heat release even under conditions of contact with water. In other words, the mixture is almost impossible to extinguish by accidental exposure.

Varieties of termite welding

There are four basic techniques for performing such welding - by means of intermediate casting, combined, end-to-end and duplex. In the process of performing the operation by intermediate casting, the powder mixture passes into the state of the liquid metal, and this does not affect the initial characteristics of the active termite substance. Usually this technique is used to mount metal structures, which are pre-mounted in the desired position. Especially for work with plate products, cathode and drainage terminals, butt-type termite welding is used, the mixture for which is pre-fired in the furnace. Combined technology involves a combination of injection molding and welding end-to-end. That is, the master can perform basic work with liquid fusing, and finish the edges with delicate welding butt. As for duplex, this method provides for the introduction of an additional stage, during which the compression of the fused gap of the structure is performed.

Applied equipment

The basis of the rigging is a crucible, which provides the ability to work with termites, including the discharge of the molten metal mass. This element can be made of ceramics or tungsten, depending on the requirements for the temperature regime. Separately prepared and molds for casting. Special matrices allow working with a wide range of molten base. Also it is necessary to prepare the equipment for termite welding in the form of clamping and fixing devices for massive structures, a special cutter and a technical pencil designed specifically for this kind of operations. Depending on the conditions of work and the requirements for the result, a special torch for the inverter and a thermometer may be required.

The practice of organizing work at home

In domestic economy this kind of welding saves those who can not properly implement the electric arc method or gas melt connection. Usually, in such cases, a termite with a minimum temperature of about 1300 ° C is used. This mode allows to provide the simplest aluminum composition, due to which it is possible to repair small cracks in metal structures, to realize car repair operations or to weld building fittings. As a rule, termite welding at home is performed without special inverters. The working tool will be a termite pencil, with the skillful handling of which you can achieve a lasting connection.

Practice of operations in industrial conditions

The industrial organization of the welding process with the use of thermite mixtures has many significant differences. First of all, more effective metal compounds with increased heat release are used. These are the same termites with the inclusion of chromium, tungsten and other elements with an active combustion function. For the technical organization of the process, it is also necessary to use more powerful equipment, that is, one termite pencil is not limited to specialists. For example, termite welding in the electrical industry necessarily involves the use of inverters, thermostats and other equipment that allows you to monitor the parameters of the workflow. The third distinguishing feature of welding in industrial sectors is the preparation of special holding equipment. Casting refractory molds are used to fill gaps, high-strength crucibles, holders and retainers for various designs.

Features of welding wires

The technology of thermite welding works best for working with electrical wiring. Moreover, this approach can be used in industry and at home. In the course of carrying out the work, an all-metal connection of the endings of the wiring is formed. It is important to note here that at the place of thickening of the wire at the welding site, the electrical resistance decreases relative to the rest of the material. For the welding itself, a special termite cartridge is used. In particular, with its help, termite welding of wires made of aluminum and steel is carried out. There are also special cartridges for working with copper wires - they are made of chill mold.

Safety during welding

For all the simplicity of this method of welding, it is precisely because of the specific chemical properties of the thermite mixtures that rather strict safety rules are determined. First, there are special requirements for the organization of storage of metallic powders. It should be stored only in dry and heated rooms. Moreover, termite welding does not allow the use of wet powders directly during the ignition process. Secondly, special requirements are also imposed on the conditions for welding. The operation can be performed only at a temperature of more than 10 ° C. The joints must be cleaned and degreased.

Pros and cons of thermite welding

Advantages include the availability of materials, the simplicity of most operations and low energy consumption during the execution of work. In other words, this option is suitable for large-scale welding of massive building structures, and for minor domestic operations. As for the disadvantages, termite welding presents a lot of difficulties in working with seamless joints. The fact is that directly in the course of the operation, the master can not fully monitor the quality of the formation of the gap and connection. As a result, it is not necessary to rely on an even and clean reduction of parts of structures without significant deformations in most cases. But in terms of strength and durability termite connections are considered one of the best.

Conclusion

Manufacturers of welding equipment mainly improve the equipment for cutting, giving high performance characteristics is a tool of thermal impact. This approach to the development of devices is justified, but the operation of equipment with increased power naturally requires large investments in energy supply. As the practice of termite welding in everyday life shows, the use of metal powder mixtures based on aluminum and magnesium on the force of cutting gives the same effect as alternative methods. Another thing is that the content of these same mixtures also requires considerable hassle and costs. But these inconveniences pay for the versatility of technology. The presence in the farm of a full range of metal powders from aluminum to tungsten will create a variety of mixtures, suitable for connecting railway sleepers, and for fine work with wires.