Titanium: welding of titanium (technology). Titanium argon welding

In aviation, shipbuilding, machine building and in some other industries, expensive materials such as titanium are used to manufacture complex and critical parts. It is good not only for its light weight, but also for the fact that this metal does not undergo corrosion processes. Let's take a closer look at what is titanium. Welding of titanium - this is quite an interesting topic for conversation, this will be discussed.

Some general information

Just take and use a piece of titanium is rarely obtained. Often it is pre-treated. It is worthwhile to understand that it is usually subjected to welding. But since this metal refers to hard-to-digest, experts have faced the problem of material destruction at a temperature of 400 degrees Celsius under the influence of water vapor, oxygen, and nitrogen. The process itself is quite complex, as it is necessary to observe a large number of technological rules, and not any kind of welding is suitable for processing this metal. In any case, today we learned how to process titanium. Titanium welding is performed by several methods:

• Electron beam;
• Arc flux;
• Argon.

Currently, all methods are popular, but the most widespread is argon welding for several reasons, which we'll talk about a little later.

Titanium and its alloys

This metal in nature is quite common. Many people say that it is not enough, but it depends on what to compare. In any case, the amount of titanium in the earth's crust is greater than copper or lead. This is a very strong metal. In pure form, its strength reaches 337 MPa, and in the alloy of the order of 1 250 MPa. The melting point of titanium is 1668 degrees Celsius.

At normal temperatures, it is resistant to corrosion and works in corrosive environments. Nevertheless, when the temperature reaches 400 degrees Celsius, its performance drops sharply. It reacts violently with nitrogen, begins to oxidize with oxygen and water vapor, which greatly limits the scope of its use. It is remarkable that the material is not at all inclined to the formation of hot cracks during welding, but its grain becomes larger, which worsens the technical characteristics of the metal and the quality of the seam. In principle, we have sorted out a little with what is titanium. Welding of titanium - that's what's interesting. Let's talk about this.

Technological features of welding

At present, one can not say that titanium is a rarity in a particular product. With him works quite a lot of manufacturers from a variety of industries. But it is necessary to understand that titanium is an active chemical element. This indicates that the use of conventional welding is unacceptable. This is due to the fact that in the process contamination occurs in the form of carbides and nitrides, which reduce the operational properties of the material.

Therefore, the main condition for welding is complete isolation from the environment. These include: oxygen, nitrogen, hydrogen, and others. In addition, welding operations must be performed at relatively high speeds. With prolonged heating, the grains in the crystal lattice expand, which greatly increases the brittleness. In any case, the welding of titanium, the technology of which will be discussed in more detail below, is a complex and responsible process. Well, now let's go further.

Titanium argon welding

The argon welding of this metal is the most popular among specialists all over the world. This is due to the fact that fluxes and electrodes are not used here, therefore, more delicate and complex welding operations are performed. In addition, the argon method for obtaining welded joints refers to high-quality welding. If the technology is observed, a high quality seam is obtained.

It is impossible not to mention the universality of argon welding. It consists in the fact that there is a possibility of processing both large-sized structures and small-sized parts. The seam is equally qualitative. In addition, welding with titanium argon is also good in that it is possible to work on a small current, and this allows the material to be welded with a thickness of 0.5 mm. Argon allows you to restore parts that have lost their original volumes.

Welding of titanium and its alloys: technology

The work must be carried out by a qualified technician with appropriate equipment. In addition, this process is multi-stage. All stages should go in a strictly established sequence and be carried out in accordance with the norms.

The first stage is preparatory. At this stage, it is necessary to clean the surface of the metal. It is extremely important to remove the oxide film. The edges are usually processed by gas-oxygen cutting. The part or blank is treated with fluorine and acid (hydrochloric acid). At the same time, a constant temperature of 60 degrees Celsius should be maintained. Here it is extremely important to protect the processed metal from the reaction with atmospheric air from both the outer and the rear. For this, copper or steel gaskets are suitable, which must be applied to the seam. In addition to the gaskets, it is permissible to use protective visors and special attachments.

In the process of welding

The process proceeds at a constant current. A special tungsten electrode is installed in the burner. When the metal comes into contact with the electric arc, a weld pool is formed. The temperature in it often reaches 6 thousand degrees Celsius.

Under the pressure of the welding arc, the molten titanium is somewhat pushed aside. It turns out that the burner burns in the groove. This can be considered an advantage, as the melting ability is greatly improved. In addition, argon is constantly injected, which provides reliable protection against the effects of oxygen, nitrogen and other harmful impurities.

Something else

Approximately and processed titanium. Cold welding involves the use of a filler wire only if the metal thickness exceeds 1.5 mm. If the thickness reaches 10-15 mm, then welding is performed by submerged arc in one pass. If the work was done in compliance with the technology, then the seam will not need to be processed from slag. It will be smooth and quality. Such compounds are characterized by high tightness and durability.

Arc and electron beam welding

Submerged arc welding has appeared relatively recently. The method is based on the isolation of material from the external environment by special fluxes. Flux is a kind of pasta. Most often used ANT-A different modifications. The peculiarity of the method lies in the fact that it was possible to achieve a better structure of the crystal lattice than in welding in an inert medium. Therefore, it is preferable to treat titanium in this way. Titanium welding by this method does not degrade the performance of the part.

Electron-beam welding has many drawbacks. But there is one significant plus, which is the complete protection of metal from the external environment. This makes it possible to obtain a very high-quality crystal lattice. At the same time, the process proceeds at a high speed, which significantly reduces the energy intensity of the work performed. There is also electroslag welding, which to date has not received proper distribution. Its peculiarity is that electrodes of the same material as the welded surface are used in the process.

Conclusion

Now you have a general idea of what welding is. Titanium, inverter welding for which it is widely used, has unique technical characteristics. That's why it is used where steel or other metals are not suitable. But the high cost of equipment for performing welding operations, the energy intensity of the process, and many other negative factors do not contribute to the development of the use of this metal. Nevertheless, some companies are constantly trying to do as much as possible in order to make it easier and easier to get a quality seam. For example, the leader in the sales of additives is the firm "Elf Villing" - "Titan". Cold welding with the help of this company is not so complicated and time-consuming. Of course, a beginner still can not cope with this task, but a specialist will be much easier to do his job. In principle, this is all that can be told about welding a metal such as titanium.