Titanium alloys are like many alloy metals. To meet the requirements for material performance, but its main component titanium accounts for more than 90%. Two alloys widely used in aerospace technology, namely Ti6A L4V6% aluminum, 4% vanadium, 90% titanium) and Ti3A L2.5V 3% aluminum, 2.5% vanadium, 94.5% titanium) Ti3A L2.5V is used to manufacture high strength The special material Ti6AL4V for pipes is mainly used for the manufacture of fuselages in the aerospace field. Titanium tubes are an indispensable material for the development of the nuclear industry. In addition to the above-mentioned uses, many equipment, pipelines and related components used in nuclear reactors, in addition to the use of zirconium and hafnium, also require a large number of titanium tubes and titanium alloy tube materials. With the further development of the nuclear industry, the value of titanium tubes will surely be more reflected.
TC4 titanium alloy is one of the most widely used titanium alloys at present, it has high strength and good corrosion resistance, but it is difficult to see seamless titanium tubes made of TC4 in the seamless titanium tube market at home and abroad. TC4 titanium materials are mainly plate-based, and TC4 titanium tubes on the market are mainly high-strength thick-walled tubes produced by hot extrusion or oblique perforation. The warm rolling process needs to improve traditional rolls, that is, on the tube rolling machine The induction heating device is installed. The processing equipment has a complicated structure, a complicated process and a high production cost. The main reason for this current situation is the high strength of TC4 titanium alloy and the difficulty of cold rolling forming. In order to solve the key technology of TC4 seamless tube cold rolling forming, the school and enterprise jointly carried out a series of studies. Such as direct cold rolling forming process to produce high-strength titanium alloy pipes, not only greatly reduces production costs, but also meets the requirements of titanium alloy high-performance applications.
Blanking method with different deformation amount is adopted, and the tube billet is rolled into a tube with a total deformation amount of 70% through two-pass and three-pass rolling. Vacuum annealing at 800 ℃ × 1h was carried out between passes. The cooling method was furnace cooling to 500 ℃ and air cooling to room temperature. Observe the changes in tissue properties. The conclusion is: under the condition of small blanking, the wall thickness deviation is small, and the surface roughness is gradually reduced; the large deformation blanking, the wall thickness deviation is large, which will affect the wall thickness of the tube obtained by subsequent rolling deviation. In the case of the same total deformation, the more rolling passes, the greater the elongation and hardness of the pipe, the higher the strength. Good overall performance. The small deformation of the billet has little effect on the anisotropy of the tube; the anisotropy of the mechanical properties in multi-pass rolling fluctuates to a certain extent. The flow of the material is strip-shaped during rolling with a large deformation amount, and the flow is in a bundle shape during rolling with a small deformation amount. Under the condition that the heat treatment conditions between passes and the subsequent rolling process are the same, the tube obtained by the large deformation amount is opened The tissue distortion is more serious.
Rolling Technology Of TC4 Titanium Alloy Tube
