Titanium alloys are like many alloy metals. To meet the requirements of material properties, but the main component of titanium accounted for more than 90%. Two alloys widely used in aerospace technology, namely Ti6A L4V6 % aluminum, 4% vanadium, 90% titanium) and Ti3A l2.5v3 % aluminum, 2.5% vanadium, 94.5% titanium) Ti3A l2.5v are used for the manufacturing of high-strength pipes. Titanium tube is indispensable important information for the development of the nuclear industry. In addition to the above purposes, a lot of equipment, pipelines and related components used in nuclear reactors are required. Besides the use of zirconium and hafnium, a large number of titanium tubes and titanium alloy tubes are also required. With the further development of the nuclear industry, the value of titanium tubes will be more reflected.
TC4 titanium alloy is one of the most widely used titanium alloys, its strength is high, corrosion resistance is good, but now it is difficult to see the seamless titanium tube TC4 material in the market. The TC4 titanium tubes on the market are mainly high-strength thick-walled tubes produced by means of hot extrusion or oblique perforation. The warm rolling process requires improvement of the traditional rollers, that is, induction heating devices are installed on the tube rolling machine. This kind of processing equipment has a complex structure, cumbersome process, and high production cost. The main reason for this situation is the high strength of TC4 titanium alloy and the difficulty of cold rolling. In order to solve the key technology of cold rolling forming of TC4 seamless tube, a series of researches have been carried out by the university and the enterprise. For example, the production of high strength titanium alloy tubes by a direct cold rolling process can not only greatly reduce the production cost, but also meet the requirements of high-performance applications of titanium alloy.
The billet was rolled into tubes with a total deformation of 70% after two and three passes of rolling respectively. In between 800 ℃ by 1 h vacuum simulated annealing and cooling methods of furnace cooling to 500 ℃ after air cooling to room temperature, observe the organization performance change. The conclusion is: under the condition of small deformation, the wall thickness deviation is small and the surface roughness decreases gradually; Large deformation and large wall thickness deviation will affect the wall thickness deviation of the tube obtained from subsequent pass rolling. Under the same total deformation, the more rolling passes, the higher elongation, hardness and strength of the tube. Good comprehensive performance. The anisotropy of the tube is not affected by small deformation. The anisotropy of mechanical properties fluctuates in multi-pass rolling. When rolling with large deformation, the material flows in a strip shape, while when rolling with small deformation, the material flows in beam shape. When the conditions of interpass heat treatment and the subsequent rolling process are the same, the microstructure distortion of the tube obtained from rolling with large deformation is more serious.