The production process begins with the extraction of rutile from various concentrates, of which rutile is more common. The concentrate is treated to remove excess iron, and the resulting material is placed in a reactor along with chlorine and carbon. The next step is the removal of impurities, which is achieved by vacuum distillation. After removing the metal chlorides, the titanium can be purified and titanium sponge is obtained. The titanium sponge is extruded and melted into titanium flakes. Titanium ingots are used in the manufacture of various products, including titanium tubes.
Manufacture of Titanium Products-Welded Tubes
In today's world, more and more companies are showing interest in the production of titanium products. They have the necessary technology and equipment to develop titanium tubes, which will be further adopted by various industries.
The development process has become routine, however, certain unique aspects are worth considering. Titanium tubing must be developed in a completely clean environment. Typically, there is a separate area used to manufacture titanium products. It is important that this area does not contain any contaminants such as dust and grease and that it is protected from exposure to moisture and air.
Welded titanium tubing is used in many industries, including chemical. Power plants, especially those operating in seawater, rely on titanium tubing. These tubes are also used for heat exchanger weights in condensers due to their high corrosion resistance.
When a joint in a weld pool is found to be not strong enough, manufacturers can apply additional tension to the titanium wall. And, to ensure that titanium products remain stable, they may rely on automated diameter measurement systems. In the future, automatic monitoring systems for seam welding conditions may also be introduced.
How is titanium tubing formed?
Titanium is formed at room temperature, similar to steel.
The ductility of titanium at room temperature is lower than that of one of the other structural metals. This automatically results in reduced stretch formability and a larger bending radius. Given this property, thermoforming is sometimes used, especially when more aggressive bending (or stretch forming) is required.
Titanium's modulus of elasticity is half that of steel, which means that the molding process can cause significant rebound (manufacturers compensate for this property). Similarly, given titanium's tendency to wear (greater than that of steel), lubrication is an important part of the tube forming process.
Forming Preparation
For the most part, titanium requires no additional measures prior to the forming operation. You can use them after receiving the ingot, but this may not always work.
After noting any marks on their surface (e.g. chisels), these will be removed by different treatments (sandblasting, pickling, etc.). . In addition, if there are sharp edges, they should be smoothed prior to the actual tube forming process. Otherwise there is a risk of cracking the edges and affecting the quality of the product.
Types of molding
Titanium tubing can be molded by both cold and hot forming.
Cold molding
Considering the elongation of the metal, titanium tubes are formed at low speed and room temperature. Therefore, a tensile test will be performed. The manufacturer will eliminate springback by thermally shaping the formed titanium tubes.
Thermoforming
It is well known that the ductility of titanium (both bending and stretch forming) increases with temperature. Therefore, titanium tubing is usually fabricated at high temperatures. As the temperature increases, the operation of forming titanium tubing becomes easier. Using this method, springback is virtually eliminated when forming grade 5 titanium (Gr5TC4).
Titanium Tube Bending
Titanium tubing is bent using conventional equipment. Mandrel benders are preferred for small radius bending. To reduce the tendency of titanium to sag to a greater extent, the bending equipment and wiper dies must be properly lubricated. For better results, the bending process should be carried out at low speeds.
How is seamless titanium tubing manufactured?
This seamless tube can be made from commercially pure titanium or one of the available titanium alloys. Titanium ingots are processed at temperatures between 850ºC and 1250ºC, reduced to 600ºC-1100ºC.
As a result of the processing, a solid billet will be obtained. It will then be transformed into a hollow block through a piercing process at temperatures varying between -100ºC and 1250ºC.
A reduction step is carried out by stretching to adjust the size. This occurs at temperatures between 600ºC and 1100ºC, resulting in a reduction of the outer diameter. A sizing step will be performed at temperatures varying between 550ºC and 1150ºC, which will further reduce the outer diameter.
